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Note: the following instructions are divided into 2 sections. Calibration Check and Calibration.
Safety Concerns
- These lights can get hot
and can burn surfaces if left stationary and on for over 20 secs. This is not an issue during normal imaging operations and will not heat the core surface. - if the cooling fans are not used. The temperature is shown on the read out above the camera and maintained at a temperature of 30 deg C. Imaging a section will cause the temperature to range between 30 and 35 deg C. If Temperature goes about 50 deg C, an alarm will sound. Notify a technician if that happens. Caution is needed when technicians perform the calibration process. Here, the lights are stationary and you must be conscious of the
length - temperature of
time - the lights
are on. - You can use the manual power switch to turn the lights on and off or the buttons in the software. Use the heat resistant grey silicone mat for the shading and pixel corrections. Do not use the plastic Gray card.
- Never look at the LEDs directly. Even the reflected light can be painful. When working under the track make sure that the power is off.
- NOTE: if you are concerned with the heat dissipation on the core surface, you can use our FLIR cameras to confirm that the temperature is ok.
Glossary of terms:
Gain: a digital camera setting that controls the amplification of the signal from the camera sensor. It should be noted that this amplifies the whole signal, including any associated background noise.
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- Note which version of standard you are using. Each color standard values vary based on the version and the manufacturer of the standard. The X-Rite Colorchecker is the preferred card to use for calibration. The program is set up to use the White and Black squares on the XRite Colorchecker (MacBeth standard). For our White is 243 and Black is 15 (Figure 21). For the QP 101 v4 card, the RGB values are 235, 111, and 80 (Figure 21). All SHIL calibration standards are found in drawer PP-2B.
- Obtain the 3D standard (Figure 20), the gray silicone mat standardand the lens cap from PP-2B.
- Set camera f/stop to either F/16 or F/22 (Figure 22). The manufacturer suggested F/22 is as the preferred for standard scanning with the current light set up ; however we have found F/16 is also acceptablework well and is the most used F/stop for calibration. For hard rock cruises, where 360° whole round scanning is required, a larger F/stop number is required.
- If you haven’t set the camera’s height, now is the time to do so! See the section Camera Height Adjustment at the end of the calibration section.
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