ADC Voltages reported do not agree with DVM measurements.

[bryn51]

for each Spec Sensor gas sensor connected to ADC Boards there are two sensor connections:
A0 (and multiples) : connects to VRef
A1 (and multiples) : connects to VGas

Here is a typical set of readings:
09:23:08.067 -> ADS1x15 ADC 0x48 Ch0: 1.472375 V
09:23:08.067 -> ADS1x15 ADC 0x48 Ch1: 2.047937 V
09:23:08.100 -> ADS1x15 ADC 0x48 Ch2: 1.386562 V
09:23:08.139 -> ADS1x15 ADC 0x48 Ch3: 2.047937 V
09:23:08.139 -> ADS1x15 ADC 0x49 Ch0: 1.398438 V
09:23:08.177 -> ADS1x15 ADC 0x49 Ch1: 2.047937 V
09:23:08.177 -> ADS1x15 ADC 0x4A Ch0: 1.399562 V
09:23:08.215 -> ADS1x15 ADC 0x4A Ch1: 2.047937 V
09:23:08.249 -> ADS1x15 ADC 0x4A Ch2: 1.401188 V
09:23:08.249 -> ADS1x15 ADC 0x4A Ch3: 2.047937 V

Vref should be approx half the supply voltage; and it is. Differences are expected due to differing bias voltages in each of 3 different types of Analog Sensor Board; suited to each gas sensor.
Vgas should be some other value greater than Vref. proportional to target gas concentration; and related to sensitivity. But in the data reported, Vgas for all of the sensors show exactly the same value. This is NOT what is expected; and indicates a problem which might be hardware or firmware.

This requires further investigation to determine if the values are credible.
Importance relates to platform setup of conversion algorithms to change voltages to gas concentration readings.
If the input voltages are not credible; then neither will be the Gas Concentration values calculated.