H-SEM
Operation
Instruction 3015-4584
13
3.10.4 Second Diagnostic Screen
PPM Level
– Parts Per Million Level is the current detected gas level, and is the volume concentration
referenced to standard temperature and pressure.
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 the purge-air bag.
3.11 Working with the P-CHK Function
3.11.1 Overview
The
P-CHK
function (Pressure Check Function) (Page 9) is useful to a service technician for
troubleshooting a flow-fault problem. The monitor will trigger a flow fault if the pressure drop from
ambient is less than 0.2 psi during a purge cycle, and 0.5 psi during a measurement cycle.
3.11.2 Keypad Functions
From the
Data Display
screen, press both
the
Keypad
Left
and
Right
buttons at the same time to
display the first
Function Menu
screen. Next, use the
Keypad
buttons to move the arrow (>) until it
points to the
P-CHK
function, and then press
ENTER
to display the
Pressure
screen.
The
Keypad Left
button toggles the purge valve open and closed. Note that an asterisk (*) appears when
the purge valve is
open
causing the monitor to draw air from the purge-air bag.
The
Keypad
Down
button toggles the pump ON and OFF.
Pressing the
ENTER
button stores the current manifold pressure shown on the left to the ambient
pressure shown on the right (must be done with the pump OFF).
3.11.3 Screen Display
Current Manifold Pressure
– Current manifold pressure in psia.
Stored Ambient Pressure
– Stored ambient pressure in psia.
Pressure Difference
– The difference between the current manifold pressure and the stored ambient
pressure.
Fault Code
– Current fault code (Page 11).
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 the purge-air bag.
0.1ppm 0.01
0.00004au 4.210v
PPM Level
µMole/Liter
Avg. Absorption Unit
∗
Detector
Voltage
14.59 AMB14.75
-0.16dif <0000>
Current Manifold Pressure
∗
Stored Ambient Pressure
Pressure Difference
Fault Code
