gamma two point cal

[tschmidt]

Concerning the gamma tool with the 3 1/8" Sondex radial bond tool (analog), which is a CSS-Gamma, the "CALBTYPE" is set to "standard" under the "software/model" panel in tool editor.  First of all, what is the reason for using the "standard" cal type?  Why is it not set to "two point", which it would appear that it should be?  Second, if you change that to "two point", there is an offset that is generated.  Where does that "offset" number come from and why is it needed?  Thanks.

[Jerry]

A standard gamma calibration only has a gain. A two point calibration has a gain and an offset. A "good" gamma tool should not require an offset. However, there are some older GM type gammas that have some "noise" counts. To get the gamma ray to correlate better, you can put in offset to profane words are not allowed the baseline of the gamma.