This user guide provides an overview of the IMS-SRM version 10.2 software application for operating the 2G Cryogenic Magnetometer. The SRM software is capable of processing section halves and discrete samples. Maintenance procedures for the SRM are outlined in the at:
Content:
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Author(s): | Beth Novak |
Reviewer(s): | Bill Mills, Katerina Petronotis |
Editor(s): |
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Supervisor Approval (Name, Title, Date): |
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Audience: | Laboratory Specialists |
Origination date: | 2016 |
Current version: | November 26, 2018 |
Domain: | Paleomagnetics Lab |
System: | SRM |
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- DAQ Move: This profile controls moves between measurement positions (leader and trailer measurements included) and the move to the drift 2 position. Set this to a reasonable speed with gradual acceleration and watch out for flux jumps. In addition, when you use the speed reduction feature to control flux jumps, this value is the base value for the reduction.
- Limit Seek: This profile is used for the following moves:
- This profile finds the limit switch location. Do not exceed 3 cm/sec. Do not use a large acceleration value, but always use a large deceleration value.
- Home Final: This profile finds the final location of the home switch. Do not exceed 3 cm/sec. Do not use a large acceleration value, but always use a large deceleration value.
- Load/Unload: This profile is used for moving the tray in and out of the SRM for general movements and moving out of the SRM to the final position prior to ending a measurement or beginning the next degaussing step.
- Drift 1: This profile is used to move to the drift 1 position and to move from the last trailer position to the drift 2 position
- Drift 2: Unused
- Degauss Stage: This profile is used to move to the degauss start position
- Degaussing: This profile is used to move the section/discrete samples from degauss stage position through the in line AF degauss coils for X, Y, and Z.
- User Define: This profile is used for testing only in the Motion Utilities (Figure 63) program.
- Click the Motion Utility button to open the Motion Utility (Figure 63) window and test the settings.
- Click Done to save the settings. Click Cancel to return to previous values.
SQUID, Degauss Controller and USB 6008 Communication and Control Setup
Figure 67- NI Max Device and Interface Menu |
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The technican should fully understand how to use this information and setup the hardware.
MAX Configuration Report
4/10/2018 3:39:21 AM
Devices and Interfaces
- NI USB-232/4 Interface "RS-232 SN:01A6252E" SQUID and DEGAUSS CONTROLLER
- 1: ASRL7::INSTR "X-SQUID"
- 2: ASRL8::INSTR "Y-SQUID"
- 3: ASRL10::INSTR "Z-SQUID"
- 4: ASRL9::INSTR "DEGAUSS"
- NI USB-485 Interface "RS-485 SN:00DCDFE3" MOTION CONTROL
- 1: ASRL6::INSTR "X-AXIS"
- NI USB-6008 "DAFFI" Analog input device used by DAFI and USB 6008 Utilities
- NI USB-232 Interface “RS-232 SN:00DCEFBB”
- 1: ASRL5::INSTR “CRYOMECH”
NI USB-232/4 Interface "RS-232 SN:01A6252E"
This is a four port USB to RS-232 serial device. With this device we connect the serial port cables from the three SQUID meters and the Degauss Controller.
It is extremely important that the alias names shown here be used. This is how the IMS software knows which instrument it is connected to. So, make sure that the alias named “X-SQUID” is actually connected to the SQUID meter and that the meter is connected to the X-axis output of the SRM. The other two axis should be treated in the same manner.
Also, be aware that if you change hardware, NI-MAX will know. You will have to delete any previously set alias names and reassign them to the correct serial ports. You must also reset the serial port communication parameters.
- Name RS-232 SN:01A6252E (if this number changes you must reconfigure!)
- Vendor National Instruments
- Model NI USB-232/4 Interface
- Serial Number 01A6252E
- Name X-SQUID
- Slot Number 1
- Port Binding COM7
- Port Description Unknown
- VISA Resource Name ASRL7::INSTR
- Port Settings
- Baud rate 1200
- Data bits 8
- Parity None
- Stop bits 1
- Flow control None
- Property Value
- Resource Name ASRL7::INSTR
- Device Type Serial Port
- VISA Alias on My System X-SQUID
- Device Enabled True
- Name Y-SQUID
- Slot Number 2
- Port Binding COM8
- Port Description Unknown
- VISA Resource Name ASRL8::INSTR
- Port Settings
- Baud rate 1200
- Data bits 8
- Parity None
- Stop bits 1
- Flow control None
- Property Value
- Resource Name ASRL8::INSTR
- Device Type Serial Port
- VISA Alias on My System Y-SQUID
- Device Enabled True
- Name Z-SQUID
- Slot Number 3
- Port Binding COM10
- Port Description Unknown
- VISA Resource Name ASRL10::INSTR
- Port Settings
- Baud rate 1200
- Data bits 8
- Parity None
- Stop bits 1
- Flow control None
- Property Value
- Resource Name ASRL10::INSTR
- Device Type Serial Port
- VISA Alias on My System Z-SQUID
- Device Enabled True
- Name DEGAUSS
- Slot Number 4
- Port Binding COM9
- Port Description Unknown
- VISA Resource Name ASRL9::INSTR
- Port Settings
- Baud rate 1200
- Data bits 8
- Parity None
- Stop bits 1
- Flow control None
- Property Value
- Resource Name ASRL9::INSTR
- Device Type Serial Port
- VISA Alias on My System DEGAUSS
- Device Enabled True
1: ASRL7::INSTR "X-SQUID"
2: ASRL7::INSTR "Y-SQUID"
3: ASRL10::INSTR "Z-SQUID"
4: ASRL9::INSTR "DEGAUSS"
NI USB-485 Interface "RS-485 SN:00DCDFE3"
This is a single port USB to RS-485 serial device. With this device we connect to the M-Drive interface board.
It is extremely important that the alias name “X-AXIS” is used. This is the means by which IMS knows which USB is connected to the M-Drive that moves the X-axis (sample handler).
Also, be aware that if you change the USB to 485 cable NI-MAX will know. Each cable has a serial number. You will have to delete any previous alias names and reassign them to the correct serial ports. You must also reset the serial port communication parameters.
- Name RS-485 SN:00DCDFE3
- Vendor National Instruments
- Model NI USB-485 Interface
- Serial Number 00DCDFE3
- Name X-AXIS
- Slot Number 1
- Port Binding COM6
- Port Description Unknown
- VISA Resource Name ASRL6::INSTR
- Port Settings
- Baud rate 9600
- Data bits 8
- Parity None
- Stop bits 1
- Flow control None
- Property Value
- Resource Name ASRL6::INSTR
- Device Type Serial Port
- VISA Alias on My System X-AXIS
- Device Enabled True
1: ASRL6::INSTR "X-AXIS"
NI USB-6008 "DAFFI"
This is an optional device and only needs to be connected should these utilities be used.
- Name DAFFI
- Vendor National Instruments
- Model NI USB-6008
- Serial Number 0164AF4C
- External Calibration
- Calibration Date 9/17/2011 12:00:00 AM
- Recommended Next Calibration 9/17/2012 12:00:00 AM
- Property Value
- ProductType USB-6008
- DevSerialNum 0x164AF4C
- ProductNum 0x717A
- BusType USB
NI USB-232 Interface “RS-232 SN:00DCEFBB"
This device is connected to the Cryomech Compressor to enable monitoring of the system.
1: ASRL5::INSTR "CRYOMECH"
- Name CRYOMECH
- Slot Number 1
- Port Binding COM5
- Port Description Unknown
- VISA Resource Name ASRL5::INSTR
- Port Settings
- Baud rate 115200
- Data bits 8
- Parity None
- Stop bits 1
- Flow control None
- Property Value
- Resource Name ASRL5::INSTR
- Device Type Serial Port
- VISA Alias on My System CRYOMECH
- Device Enabled True
SRM Maintanence Procedures
The following section includes instructions on how to:
- Release Trapped Flux from within the SRM
- Measure the Response Lengths of the SQUIDS
- Check the Degauss Coil Function
- Collect a Field Profile within the SRM
- Check the Calibration Factors for the SQUIDS
Releasing Trapped Flux
When magnetically strong materials are passed through the SQUID measurement region it is possible to trap flux within the SRM. This is particularly a problem after hard rock expeditions. The best way to recognize trapped flux is by monitoring the SQUID readouts for extra noise and drift. Trapped flux cannot be measured with the Fluxgate magnetometer.
To release trapped flux:
- Connect the oscilloscope to the SRM so that the signal wave form can be monitored
- Oscilloscope Aux IN to Model 581 DC SQUID System Z axis SYNC
- Oscilloscope Channel 1 to Model 581 DC SQUID System Z axis AC Output
- Do not hook up the nulling coil cables. 2G recommends attempting to release the trapped flux without the nulling coils first and checking the resulting field and performance of the SQUIDS.
- Heat up the SQUIDS using the Model 202 Control Monitor until the oscilloscope signal becomes a flat line.
- Turn on the SQUID and Stripline heaters. Press and hold the shield heater button until the red indicator turns on.
- The oscilloscope signal should be lost when the temperatures reach 7 K. Once the signal has become noisy, continue to step 3.
- Turn off the heaters and allow the system to cool
- Measure the trapped field within the SQUID region using the Fluxgate magnetometer
- Measure a full field profile and save the data to the Field Profile folder in IODP Share: Pmag Documents
- If it appears that a high field was trapped within the SQUIDS it may be necessary to go through the entire field trapping procedure (See appendix B).
- Record the temperatures of the shields and SQUIDS on the SRM log sheet once the system has settled.
Measuring SQUID Response Lengths
Each SQUID has a unique response length based on the geometry of the system and the SQUID orientation. To measure the response lengths of each SQUID you may use a point source. The point source must be moved through the sensor region of the SRM over a distance longer than the length of the response functions. The measurements must be made 3 times, once for each axis. The point source will need to be adjusted between each measurement so that the axis of the source is aligned along each of the axis of the magnetometer. The point source should be centered in the bore of the SRM. Using the discrete boat, but running the system as a section half can help facilitate this. Recommended point sources for these measurements are the AGICO JR6 standard (Do not demagnetize this standard!), black plastic cube with a metal pin, or the Applied Physics Calibration coil. The recommended method is using a cube with a point source. Using the calibration coil for these measurements is time consuming and labor intensive.
Measuring a Response Curve using a point source cube:
1) Set the measurement interval to 2 mm in the DAQ> Measurement Editor menu and set the Leader/Trailer length to 0 cm (Figure 9).
2) Set the tray length to 50 cm in the DAQ> Section Tray Editor menu (Figure 6).
3) Collect a section half background measurement for the empty tray by selecting DAQ> SRM: Section Background from the IMS-SRM menu.
4) Place the point source in the discrete sample boat with the point source in the X position. Make sure the point source is positioned so that it is centered in the bore of the SRM.
- Positioning the cube at 20 cm in the tray is recommended.
5) Select Start in the IMS-SRM software (Figure 2).
6) Select an archive section half sample type and orientation on the left hand side of the screen (Figure 22.
7) Ensure the measurement sequence is set to NRM only (Figure 20). DO NOT DEMAGNETIZE THE STANDARD!
8) Select the Manual sample entry tab and enter a sample ID and LIMS ID for the test (Figure 23).
- Suggested naming convention includes which axis is aligned with the SQUID. i.e. Sample ID: Standard Cube; LIMS ID: Response Length-X axis
9) Enter a User Length for the ‘core’
- A length of 20 cm on each side of the point source should cover the entire response region for all three axes. i.e. If the cube is at 20 cm the user length should be set to at least 40 cm.
10) Select USE ID and Length Values and press the Measure button
11) The tray and sample will move through the measurement region collecting a measurement every 2 mm over the selected user length.
12) When the measurements are complete, the data will be written to a standard .SRM file and placed in the IN folder and to a .csv file in the AUX Data: SRM: Section folder. The .csv file will be the most useful.
13) Reposition the point source so that the Y axis is aligned with the Y SQUID and complete steps 8-10 again.
14) Reposition the point source so that the Z axis is aligned with the Z SQUID and complete steps 8-10 again.
Measuring a Response Curve using the Applied Physics Calibration Coil:
1) Position the Applied Physics coil in the section half boat. Center the coil in the bore using putty or foam to raise the coil off the bottom of the tray.
2) Connect the calibration coil to the calibration coil power supply via a BNC cable.
- The cable should be long enough to allow the coil to travel through the measurement region while the power supply remains on the desk.
3) Set filter on Model 581 DC SQUID system box to 100 HZ.
4) Connect multimeter to the Output of the X axis SQUID. Set the mulitmeter to measure AC voltage.
5) Set the power supply box to AC and turn on the power supply
6) Open the IMS-SRM Motion Widget
7) Move the calibration coil into the SRM while monitoring the voltage read out on the multimeter. Find the peak voltage.
- This position will vary depending on where the coil is positioned in the boat.
- According to Bill Goodman the peak voltage for Z axis should be approximately 1.05 V but the transverse coil value will be reduced by a factor of two.
8) Move the coil back toward home by 20 cm
9) Record the position of the tray from home and the AC Voltage displayed on the multimeter for this position
10) Move the coil forward by 1 cm and record the voltage again.
- Repeat this process until you have gone 20 cm past the center of the coils.
- A smaller measurement increment can be used if more resolution is desired.
11) Move the calibration coil back to the home position.
12) Reposition the coil for the Y axis and connect the BNC cable from the multimeter to the Y axis SQUID display. Repeat steps seven through 11.
- To switch to the Y axis, rotate the entire coil wand 90 degrees
13) Reposition the coil for the Z axis and connect the BNC cable from the multimeter to the Z axis SQUID display. Repeat steps seven through 11.
- To switch to the Z axis carefully unscrew the coil from the wand and reorient the coil and reattach
14) Compile the recorded data (offsets and voltages) into a single spreadsheet.
Calculating Response Length:
1) Open the .csv files associated with the response length measurements in Excel to view the X, Y, and Z moments.
2) Compile a worksheet with the following columns: Offset, X moment, Y moment, and Z moment
- The X moments should be taken from the measurement when the point source was in the X position, etc.
3) Response length calculations will not work if the peak moment is a negative value. If the axis was measured in the negative direction, multiply all of the moment values for that axis by -1.
4) Normalize each set of moment values
- Find the peak moment value for X and divide all of the X moments by this value. Do the same for Y and Z.
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Figure 68- Kaleidagraph Data Table.
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6) Plot 3 scatter plots of normalized moment vs offset, one for each axes
- The graphs should have a bell curve shape with slight negative lobes (Figure 69).
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Figure 69- Example graph of normalized moments vs offset.
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- When the data table (Figure 68) is selected in Kalediagraph, a MACROS menu is available at the top of the page. Select Integrate-Area from this menu.
- In the next window, enter which column of data is the X axis and which is the Y axis of your plot (Figure 70). X should be offset and Y should be the moment values. Select OK.
Figure 70- Prompt window allowing user to select data to use for the integrate area function.
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Figure 71- Prompt window allowing user to select the area of the curve to use for the integrate function.
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- The value reported is equal to the response length (Figure 72). These values should range from 7 to 9 cm depending on the SQUID axis.
Figure 72- Integrate Area Results window.
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8) Compare the results obtained in these response length measurements with the response length values stored in the SRM setup window (Figure 4). Make sure you are confident in the values you calculate before considering changing the values used in the SRM software.
Check Degauss Coil Function
The function of the degauss coils should be checked periodically to ensure the desired fields are being produced. For this procedure, you will need the axial and transverse Hall probes and the model 6010 Gauss meter. Each coil will require a separate measurement. The Z coils is measured using the axial probe. The X and Y axes are measured using the transverse probe.
Measuring the field produced by the degauss coils:
- Secure the Axial probe in the section half tray with probe end centered at 140 cm from the home switch. The probe should be centered in the bore (Figure 73).
Figure 73 Hall probe in the Z axis orientation |
Figure 74 Degausser Control unit. Red box indicates the toggle switch for switching to manual mode. Green box indicates the dial for setting the alternating field in Gauss. Blue box indicates the axis selector control. |
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- Connect probe to Gauss Meter and turn the meter on.
- Set the units to mT and select AC mode on the Gauss Meter. Make sure the meter is in automatic range mode.
- Select Motion> Motion Widget from the IMS menu.
- Move the tray into the SRM so that the Hall probe is positioned within the Z degauss coil region.
- For the Z axis with the probe near 140 cm in the tray, the peak field should be found near 261 cm from the home switch.
- Set the maximum field value on the Degausser controller.
- The controller is operated in Gauss, so a value of 200 on the dial is equal to 20 mT. Do not set a high field. The coils will be on for an extended time during the tests and may heat up.
- Press the Ramp Up command on the degausser controller.
- Once the Tracking light turns on adjust the position of the Hall probe using the motion widget until the peak value is found.
- Using the HOLD (Max) features of the meter may help to identify the actual peak value as the meter is moved through the degauss coil region.
- Record the peak value.
- The value displayed on the Guass meter in AC mode is a true RMS value of the waveform with the dc component removed. To correct the read out value to mT multiply by the RMS correction factor of 1.414.
- Example: Degauss unit set at 20 mT. Read out on Guass meter is 15.81 mT. Actual produced field is 22 mT.
- Press the Ramp Down button on the degausser controller.
- Move the tray to the Home position using the motion widget.
Figure 75 Hall probe in the X axis orientation |
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- Set the axis selector on the degausser controller to X.
- Use the motion widget to move the probe into the X degauss region and repeat steps 8 to 12.
- If the probe is positioned at 140 cm in the tray, then the peak field should be found near 243 cm from the home switch.
Figure 76 Hall probe in the Y axis orientation |
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- Set the axis selector on the degausser controller to Y.
- Use the motion widget to move the probe into the Y degauss coil region and repeat steps 8 to 12.
- If the probe is positioned at 140 cm in the tray, then the peak field should be found near 277 cm from the home switch.
- When finished with testing, set the degausser controller back to computer mode. The IMS software may need to be restarted after the mode has been changed back.
Measuring the Field Profile within the SRM
At the start of each expedition, the field profile within the SRM should be measured using the Fluxgate magnetometer and the DAFI utility in the IMS-SRM software. This data is retained in IODP Share> Pmag Documents: SRM: Field Profiles as .xlsx files. The field within the SQUIDS should be in the 0 to 20 nT range. If the field within the SRM is determined to be high, the field trapping procedure outlined in Appendix B should be followed.
Collecting a field profile:
- Position the Fluxgate magnetometer in the section half boat. The magnetometer should be centered near the 140 cm mark to ensure there is enough cable to measure along the entire track.
- Connect the USB6008 BNC cables to the back of the Fluxgate Control box.
- Set the range of the fluxgate to 10 mOe.
- This range will be too sensitive for outside of the shields, but should be appropriate within the measurement region.
- Open the DAFI program in the IMS-SRM program
- Set the in tray offset, DAQ Interval, average, and range in the DAFI window.
- Set the start and end offset.
- These are the track positions between which the measurements will be taken with the DAFI program. The Fluxgate will be moved to the start position before any measurements are taken.
- Recommended offsets if Fluxgate is positioned at 140 cm in the tray are:
i. Start offset: 150 cm.
ii. End Offset: 400 cm.
- Select Start and monitor the cable of the fluxgate as the tray moves through the SRM.
- A .csv file will be written to C: AUX_Data\DAFI.
- These files contain the X, Y, and Z meter values in mOe as they would be read from the Fluxgate magnetometer displays and the meter values converted to nT.
- Save the file as an .xslx file in the IODP Share> Pmag Documents: SRM: Field Profiles folder
- It is recommended that a plot of the field along each axis vs offset be created.
- Monitor for significant changes in the field or areas of leakage in the shielding.
It may be necessary to conduct multiple measurements using different ranges of the fluxgate, depending on what information is desired. The field around the shield joints will be too high for the 10 mOe range, but the 1000 mOe will not be sensitive enough for the measurement region of the SRM.
Checking SQUID Calibration Factors
Applied Physics provided calibration factors for the SQUIDS upon delivering the SRM. This procedure is done using a speciality calibration coil which is used for each system they produce. Applied Physics also provided a calibration coil to IODP, but it is not identical to the original coil.
The Applied Physics coil calibration constant is:
C= 3.252 emu/A
The calibration factors should not be altered in the SRM software without serious consideration. The IODP coil can be used to check the calibration factors if the user wants to verify the systems function.
Figure 77 Calibration coil orientations. A) Z axis, B) Y axis, and C ) X axis. D and E illustrate how to reposition the coil on the wand. |
A |
B |
C |
D |
E |
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Be aware that proper experiment setup is critical to obtaining valid results. If the coil is not centered in the SQUIDs, the SQUID signal and voltages measured will be inaccurate. It is best to do these measurements when the ship is stable.
Applied Physics calibration constants for the SQUIDS:
CX= 8.1036 E -5 emu/Φ0
CY= -8.2590 E -5 emu/Φ0
CZ= 3.8825 E -5 emu/Φ0
Supplies needed:
1) 4 BNC cables
2) Oscilloscope
- Adjust the settings to a horizontal scale of approximately 4.00µs and the vertical scale to approximately 2 V.
- Set the oscilloscope source to AUX
3) Multimeter
4) Applied Physics calibration coil and power supply
Measuring and Determining the SQUID Calibration factors:
1) Connect the Calibration coil to the power supply and set supply to DC mode
2) Connect Aux In on the oscilloscope to the Sync on the back of the Model 581 DC SQUID system
- The coil orientation should correspond with the Model 581 DC SQUID system, i.e. if connected to the Z axis Model DC SQUID system, ensure the coil is in the Z position
3) Connect Channel 1 on the oscilloscope to the AC Out on the back of the Model 581 DC SQUID system
4) Adjust the potentiometer (pot) on the calibration coil power supply to zero (turn knob all the way counter clockwise)
5) Set the Model 581 DC SQUID system to 100 HZ filter
6) Center the coil in the SQUIDS.
- To find the center of the SQUIDS with the calibration coil:
i. Connect the multimeter to the Output on the front of the Model 581 DC SQUID system. The SQUID should be locked.
ii. Set the calibration coil power supply and the multimeter to AC
iii. Move the coil into the SQUIDS using the Motion Widget utility in the IMS software.
iv. Find the peak voltage. This should be the center of the SQUIDS.
* If the coil is not properly centered, the oscilloscope signal and voltage reading will be inaccurate and the final SQUID calibration constant will be incorrect.
7) Disconnect the multimeter from the output of the Model 581 DC SQUID system.
8) Connect the mulitmeter to the calibration coil power supply X mon port
9) Set mulitmeter and calibration coil power supply to DC
10) Unlock the SQUID using the black button on the front of the Model 581 DC SQUID system
11) While monitoring the signal on the oscilloscope, adjust the pot on the calibration coil power box to the first double frequency point, and then continue to the second double frequency point.
12) Record the voltage from the multimeter while at the second double frequency point.
- This voltage will be used to determine the SQUID calibration constant
13) Return the tray and coil to the home position using the IMS Motion Widget
14) Repeat steps 4 through 13 for the remaining two coil axes.
- Remember to switch the BNC cables to the appropriate Model 581 DC SQUID system ports.
*Once measurements are complete, make sure to LOCK the SQUIDs.
Calculating the SQUID Calibration Constants
Using the formulas and Cx,y,z= C x I, calculate the coil calibration factor,
V= Voltage measured
R = 500,000 Φ0=Resistance
I= Current
C=3.252 emu/A =Coil Calibration Constant
Cx,y,z=Coil calibration factor (emu/Φ0)
Example Calculation of SQUID calibration constant:
If the measured voltage is 12.27 V,
Multiply this value by the coil calibration constant to get the Calibration Constant for the SQUID:
The resultant values should be similar to those provided by Applied Physics.
IODP measured calibration constants for the SQUIDS during Exp 372:
CX= 8.66 E -5 emu/Φ0
CY= -8.19 E -5 emu/Φ0
CZ= 3.56 E -5 emu/Φ0
Appendix A: Cryomech Compressor and Haskris Water Chiller
This guide is intended as an overview of the operation of the SRM compressor and includes instructions for use of the Haskris Chill Water system. For in depth operational instructions, see the Cryomech Compressor vendor manual and the Haskris Air Cooled Water Chiller vendor manual.
The Superconducting Rock Magnetometer (SRM) uses a cyro-compressor to keep a small amount of Helium compressed in order to reach superconducting temperatures. The compressor is water cooled.
Chill Water Sources:
The ship’s chill water is plumbed directly to the SRM Cryomech 2800 series compressor through a heat exchanger coil (Figures A1 and A2). This system is comprised of a chilled input line and warm water return line. The heat exchanger coil is used to warm the ship’s chill water before it reaches the compressor. These lines are plumbed through a set of three way valves at the forward end of the paleomagnetics lab.
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Monitoring Compressor status:
To monitor the status of the compressor, use the CryoWATCH program (Figure A4) which is available on the SRM computer. The compressor is connected to the SRM PC via an RS232 cable. The application displays the status of the compressor and logs these values to a text file (Figure A5). The communications setup should be the default baud rate of 115200 and a slave address of 16. The com port may need to be adjusted. The current configuration requires com port number 5.
| Minimum | Maximum |
He Gas Temperature | - | 190 F |
Oil Temperature | 60 F | 100 F |
He Gas Pressure | 35 PSIG | 399 PSIG |
H20 In Temperature* | 40 F | 80F |
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Because of the low temperature of the incoming chill water, it is important to set the flow rate using a metering valve found at the forward end of the paleomagnetics lab (Figure A6). You should set the flow rate as high as possible while keeping the compressor’s oil temperature above 60 F (temperatures in the 80s or 90s are better). Make small adjustments when turning the valve as reducing the flow too far will cause the compressor to shut down and give a “low flow” error. If this happens, open the valve again to the previous position and press the ON button on the compressor to restart the system. Monitor the oil tab after adjusting the metering value to ensure the temperature stays within the appropriate range.
Alternative: If CryoWATCH is unavailable, the Cryomech Virtual Panel with Logging panel is available. This can be found on the SRM desktop at C:\Users\daq\Desktop\cryomech\Cryomech\virt_panel. Set the com port number to 5, designate a file path, and the compressor data will be logged.
Trouble Shooting
If you notice the SRM area is unusually quiet and/or an audible beep is coming from the compressor, check the front panel of the compressor (Figure A7). It will display the fault that has caused the compressor to shut down. Check the Cryomech Compressor user guide in IODP SHARE for error messages and how to handle each.
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The chill water is still flowing, but is no longer refrigerated: Monitor the oil temperature using the CryoWATCH Software and increase the flow rate with the metering valve as necessary. Remember, even chill water at 80 F can keep the compressor running.
Ship’s chill water is off: The Haskris will need to be turned on to supply chill water to the compressor. The compressor will not shut down if you momentarily interrupt flow, only if the temperature of compressor’s oil rises too high or if the flow is shut off completely.
Switching Chill Water Systems
The ship’s chill water may be shut down for routine maintenance or repair. In this situation, the crew should notify the technical staff prior to the shutdown. This will allow a technician to switch to the backup Haskris system before the chill water is shut down, preventing the compressor from shutting down and allowing the SRM system to continue working uninterrupted.
If the ship’s chill water system shuts down unexpectedly, the compressor will shut off, beep audibly, and signal a “low flow” error on the front console of the compressor. You have approximately 10 minutes from the time the compressor shuts off to the time when the SRM warms above 7 K and loses the trapped field.
From ship’s chill water to Haskris water chiller supply:
1) Open the Haskris water tank cover to monitor the water level. (Figure A8).
The Haskris is filled with tap water or ship’s chill water. If you open the tank and the surface of the water is growing biologic experiments, it is best to empty the tank with a wet vacuum and refill the Haskris water tank before starting the system. If the ship’s chill water is still on, the tank can be filled by opening the outlet 3 way valve and allowing the water returning from the compressor to flow into the Haskris for a short period of time. If the ship’s chill water is off, fill the Haskris tank with clean, drinkable water (Not Deionized water!) via a bucket. ROUTINE MAINTENANCE -> At the end of every expedition, remove the water, clean and replace with drinkable water.
2) Turn on the Haskris power using the switch on the front of the Haskris (Figure A8). Wait 10 seconds. The Haskris is a closed loop system and can be started before the water supply is diverted as long as there is water in the Haskris tank. If the water level drops significantly, add more water to the tank before opening the valves.
3) Use the up and down arrows to set the desired water temperature for the water leaving the Haskris (Figure A8). The water temperature should be set at 65 degrees F or above. Remember, the goal is to keep the compressor oil temperature as close to 90 degrees F as possible.
4) Locate the black 3 way valves at the forward end of the paleomagnetics lab (Figure A9).
When the ship’s chill water is used to supply cold water to the SRM compressor, the valves should point toward the chill water lines (white arrows pointed toward the right when facing aft) (Figure A10).
5) Turn both valves 180 degrees. This can be done simultaneously or one at a time. This step should be done quickly to avoid completely draining the Haskris water tank or overfilling the tank. Make sure the valves are turned the full 180 degrees.
When the Haskris water chiller is used to supply cold water to the SRM compressor, the valves should point toward the Haskris water lines (to the left when looking aft) (Figure A11).
6) Once the valves are turned, monitor the compressor vitals using the CryoWATCH software on the SRM computer. Monitor the water temperatures and oil temperatures on the right hand side of the screen.
To switch back to ship’s chill water from the Haskris, turn the valves back to the original position (Figure A10). Turn off the Haskris and monitor the oil temperature in the CryoWATCH software.
Appendix B: SRM Field Trapping Procedure
This guide is intended to assist technical staff with trapping a low magnetic field inside of the SQUID response region. This procedure will need to be done any time the SRM warms to temperatures above superconducting (7 K) or if a large trapped field is suspected within the SQUID response region.
Prior to beginning this process, check the fluxgate zeros in a mu-metal shield. Zero the fluxgate if necessary. Measure the field trapped inside the SRM prior to heating and retrapping a field to obtain a baseline measurement. For further instructions on measuring the trapped field, see the the DAFI utility instructions.
Items needed for trapping a low field:
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Trapping a Low Field
- Position the fluxgate probe in the section half boat. Center the fluxgate in the bore (Figure B5). Note the position of the fluxgate from zero.
- It is recommended to center the fluxgate coils around 150 cm in the boat.
- Put the fluxgate control box in range 10 mOe for measurements within the SRM shielding.
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- Connect the nulling cable to the back of the Model 202 Control Monitor and to the ports near the junction between the measurement region and the degauss region (Figures B7 and B8)
- Connect the Model 202 Control Monitor Rock Mag port to the RS232 port on the cold head (Figure B9).
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- Keep turning on the Shield heater while monitoring the TSH and TSQ temperatures. When TSH and TSQ are approximately 11-12 K, turn off all of the heaters.
- Center the fluxgate magnetometer in the SQUIDS using the Motion Widget utility. The SQUIDS are 295.7 cm from the home switch.
- If the compressor is off, turn it on and increase the water flow rate.
- While monitoring the readouts on the fluxgate, use a small screw driver to turn the nulling coil potentiometer on the control monitor box (Figure B11 and B12). Adjust the fluxgate readouts to as close to zero mOe as possible.
- The nulling coil potentiometers do not correspond to the fluxgate axis. The X nulling pot adjusts the Y axis, the Y nulling pot adjusts the X axis, and the Z nulling pot adjusts the Z axis.
- The values are in mOe so a value of 2.14 on the fluxgate in range 10 mOe is equal to 214 nT.
- The X, Y, and Z readouts correspond to the fluxgate magnetometer axes, not the SRM axes.
- The Z axis readout is missing its decimal point. The decimal should be in the same position on each readout.
- Continue monitoring the fields and the TSH and TSQ temperatures as the system cools down. Superconducting temperatures are around 7 K.
- It is possible to continue adjusting the fields until the shield goes superconducting. It will be evident that the shield has gone superconducting when the adjustment of the nulling currents no longer has an effect on the field.
- Once the system is superconducting, move the fluxgate 20 cm towards home. A clean signal should be visible on the oscilloscope.
You will notice some fluctuation on all axes, but the Z axis may show significant drift after trapping a new field. Allow the system to settle before taking any measurements. Use the fluxgate magnetometer and DAFI utility in the IMS SRM software to measure the trapped field across the SQUID centers once the system has settled.
Figure 1- SRM Desktop Icon
Figure 2- SRM IMS Main Window
Figure 3- IMS Control Panel Drop Down Menus
Figure 4- SRM Parameters Window
Figure 5 Degauss and Drift Position Configuration Window
Figure 6- Section Tray Editor Window
Figure 7 Discrete Tray Editor Window
Figure 8 Tray Editor Warning Window
Figure 9 Measurement Editor Window
Figure 10 DAQ Invalid Warning in Measurement Editor Window
Figure 11 Section Tray and Discrete Tray Background Windows
Figure 12 Background Confirmation Window
Figure 13 Sequence Editor Window
Figure 14 Offline Treatment Window
Figure 15 Copy Sequence File Window
Figure 16 Sample Preset Editor Window: Section Half View
Figure 17 Sample Preset Editor: Discrete Sample View
Figure 18 Edit Preset Window- User may name a new preset, update an existing preset, or disable a preset button from this window.
Figure 19 Clear Presets Confirmation Window
Figure 20 Sample Information Window: Measurement Sequence Selection
Figure 21 Sample Information Window: Section Half Scanner Sample Entry
Figure 22 Sample Information Window: Section Half LIMS Entry
Figure 23 Sample Information Window: Section Half Manual Entry
Figure 24 Sample Information Window: Discrete Scanner Sample Entry
Figure 25 Sample Information Window: Discrete LIMS Entry
Figure 26 Sample Information Window: Discrete Manual Entry
Figure 27 Sample ID, LIMS ID, and Tray Information
Figure 28 - Discrete Sample Entry Error Message
Figure 29 Webservice Connection Error
Figure 30 Checking LIMS-JR Webservice Connection Window
Figure 31 Network Status Indicator
Figure 32 Invalid background measurement warning message
Figure 33 Mismatched label and preset warning message
Figure 34 SRM Display during Measurement
Figure 35 Degausser Internal Error Window
Figure 36 SRM User Abort Window
Figure 37 Motor Power Turned off Warning
Figure 38 Degauss Abort Warning Window
Figure 39 Degauss Status Window
Figure 40 Hardware Emergency Stop Button
Figure 41 Pause and Confirm Button
Figure 42 Pause and Confirm Window
Figure 43 Exclude Intervals Window
Figure 44 Exclude Intervals Indicator
Figure 45 MagSpy Desktop Icon
Figure 46 MagSpy Data Visualization Window
Figure 47 Flux Jump Warning after a measurement
Figure 48 - Reduce Speed Drop-down Menu
Figure 49 - LIMS filter setup window
Figure 50- Time Series Utility during Measurement
Figure 51-DAFI Utility Setup Window
Figure 52-U-Turn Utility Window
Figure 53- Close up of U-Turn Mode Selection Drop Down Menu
Figure 54- U-Turn Utility Corrected File Display
Figure 55- U-Turn Utility Sample Comparison Window
Figure 56- USB6001 Device
Figure 57- Motion Widget Window
Figure 58- USB6001 Utility Window
Figure 59- Data Recovery Utility Window
Figure 60- Degauss Utility Window
Figure 61 - MDrive Motion Setup
Figure 62- SRM Motor and Track Options Setup Window
Figure 63- Motion Utilities Window
Figure 64- SRM Fixed Positions Window
Figure 65-SRM Limit and Home Switches Window
Figure 66 - Motion Profiles Window
Figure 67 – NI Max Device and Interface Menu
Figure 68 – Kaleidagraph Data Table
Figure 69 – Kaleidagraph Example Graph
Figure 70 – Kaleidagraph Prompt 1
Figure 71 – Kaleidagraph Prompt 2
Figure 72 – Kaleidagraph Prompt 3
Figure 73 – Hall Probe Z axis
Figure 74 – Degausser Control unit for hall probe measurements
Figure 75 – Hall Probe X axis
Figure 76 – Hall Probe Y axis
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