ACD Trending from AcdLeHeBias runs

The AcdLeBiasCal script pulses the scans the bias_dac and measures the pedestal at each point
We do this for both the low range and high range readouts.
For each readout we measure the following values.

• Offset: the pedestal value if the bias_dac were set to 0
• Slope: the rate of change of pedestal / bias_dac.
• Set point: the value of bias_dac that makes the pedestal as low as possible, but at least 100

Since we only have one bias_dac for both the low and high ranges the final set point is the lower of the set point for the two ranges.
The test points here are the "CPT" tests list in the full list of ACD test phases

Comments:

• Both the fit parameters and the resulting set point show quite a bit of temperature dependence.
  This is visible in the GSFC TVAC runs (phases 3-8) and the NRL TVAC cold(29,31) runs.
• The discrepencies in phases 12-14 are in the GAFE 17 channels.
  These occur because varying amounts of noise fed into those channel when the hold_delay changed
  

Plot of values	Comments	Plot of diff W.R.T. reference
	Intercept of pedestal v. bias_dac curve. This plots is for high range readout Range: 0 - 2000
	Slope of pedestal v. bias_dac curve. This plots is for high range readout Range: -150 - -110
	Mininum bias_dac which gives pedestal 100 pha counts This plots is for high range readout
	Intercept of pedestal v. bias_dac curve. This plots is for low range readout Range: 0 - 2000
	Slope of pedestal v. bias_dac curve. This plots is for low range readout Range: -150 - -110
	Mininum bias_dac which gives pedestal 100 pha counts This plots is for low range readout
	Mininum bias_dac which gives pedestal 100 pha counts for both ranges.