Brochure

CO
2
Monitor Operation
Instruction 3015-9000 Rev 2 15
2.13 The DIAG Function
2.13.1 Overview
The DIAG function displays sensor data and status information useful to a service technician for troubleshooting
various fault conditions. Explanations of the data shown in these screens are given below.
2.13.2 Keypad Functions
From the Data Display screen, enter the Function Menu screen. Next, use the Keypad buttons to move the arrow
(>) until it is next to the DIAG function, and then press ENTER to display the first of two Diagnostic screens.
Press the Keypad Up button to toggle between the First and Second Diagnostic screen.
2.13.3 First Diagnostic Screen
Bench Voltage →
Detector Temperature °C →
← Fault Code
← Pressure Reading
Noise →
Box Temperature °C →
← Fault Code
← Pressure Reading
In the First Diagnostic screen, the user can toggle between displaying Bench Voltage / Detector Temperature, and
Noise / Box Temperature by pressing the Keypad Right button.
Bench Voltage – This is the current peak-to-peak output of the IR detector. In the absence of gas this value can
range from 3.90000V to 4.50000V.
Noise –The Noise value is a 16 point running average of the noise portion of the IR detector’s output. This reading
is valuable mainly when gas is NOT present.
Detector Temperature – This is the current detector temperature in °C.
Box Temperature – This is the current internal enclosure temperature in °C.
Fault Code – Current fault code.
Pressure Reading – This is the pressure as measured every purge cycle with the sample pump off and the gas-
sample inlet open. Its value is weather and altitude dependent and can range from 10.0 to 15.5 PSIA.
Purge Valve Asterisk (∗) – The purge valve can be opened and closed by pressing the Keypad Left button. An
asterisk appears on the display when the purge valve is open causing the monitor to draw air from its internal
purge-air bag.
2.13.4 Second Diagnostic Screen
PPM Level →
Average Absorption Unit →
← µMole/Liter
← Detector Voltage
PPM Level – Parts Per Million Level is the current detected gas level relative to purge air. (When the purge air bag
is filled, the CO
2
concentration it contains is subtracted from all subsequent measurements. So if the bag contains
normal outdoor ambient CO
2
at 386 ppm and you then measure outdoor ambient, the display will show 0 ppm.)
Average Absorption Unit – This is the optical absorbency. In the absence of gas the absorbency is 0.00000 au.
When sampling gas, its value varies proportionally with the gas concentration.
µMoles/Liter – This is the absolute concentration in micro-moles per liter of gas.
Detector Voltage – This is a running average of the IR detector’s bench voltage.
Purge Valve Asterisk (∗) – The purge valve can be opened and closed by pressing the Keypad Left button. An
asterisk appears on the display when the purge valve is open causing the monitor to draw air from its internal
purge-air bag.