A: The following describes how to read and make sense of the 3 gas measurements on the analog output as well as the general RS-232 output.
Analog out:
To display all values-
select CYCLE for analog channel 1
select GID for analog channel 2
The analog outputs will cycle Benzene -> Toluene -> Xylene
The output for each will persist for about 4 seconds and then advance to the next gas.
Channel 1 will set a voltage/current proportional to the desired (selected) range for that gas.
Channel 2 will set an identifying voltage/current indicating the gas referenced on Channel 1:
Benzene: 1/5 of scale
Toluene: 1/2 of scale
Xylene: 4/5 of scale
Note: If Auto Ranging is enabled, there is no way to indicate which of the ranges a gas may be currently set on. Therefore, Auto Ranging is not advisable when using the CYCLE/GID feature of the analog outputs.
To set the Range:
- set Range Select: MAN (strongly advised)
- Auto Range Src: Don't care
- Man Rng BZ/TO/XY to desired range
- R1/R2/R3 to desired range value
RS232 output:
- on startup, the MODEL and VERSION are transmitted
- at the end of each measurement period the following is sent:
BZaV: Value, Integrated Value, Integration Sum, Calculated Baseline
TOaV: Value, Integrated Value, Integration Sum, Calculated Baseline
XYaV: Value, Integrated Value, Integration Sum, Calculated Baseline
- at the end of a span the following is sent:
BZsV: Value, Integrated Value, Integration Sum, Calculated Baseline
TOsV: Value, Integrated Value, Integration Sum, Calculated Baseline
XYsV: Value, Integrated Value, Integration Sum, Calculated Baseline
(note the 's' as the 3rd character)
(note that Value should be identical to Integrated Value)
(note Integrated Sum and Baseline correspond to a measurement of 'Volt Seconds' which is associated with the response of the detector and the basis for the analysis)