TROUBLESHOOTING
7-4
3. PID Lamp Parameters
This function applies to monitors equipped with a PID
sensor. Drv is the lamp drive and is not adjustable from the
standard value of 200. Lamp is the lamp current draw. Fail
is an adjustable failure threshold. Use [N/-] and [Y/+] to set
the Fail about 10 counts lower than the lamp reading. The
asterisk appears by the previously stored value:
Drv
Lamp
Fail
200
84
*80
4. CO
2
Raw Counts and Bias
The CO
2
sensor output is connected to two amplifiers. CO
2
is for the CO
2
signal and Ref is for the reference. The
display shows the current bias setting. When zero gas is
applied, CO
2
should read a lower value, while Ref should
display almost no change. When a CO
2
gas is applied, CO
2
output should increase. The bias value is adjustable but
should not be changed.
CO
2
REF
Bias
4136
4139
*255
5. Toxic Gas Sensor and Raw Counts
The raw output of the toxic gas sensor is displayed. Some
sensor types use the ToxA channel, while others use the
ToxB channel indicated by an asterisk on the left is
operative. Use the [N/-] or [Y/+] to toggle between x1 and
x10 gains. When zero gas is applied, both signals should
be between 200 and 500. When a toxic gas is applied, both
signals should increase; the increase of x1 gain should be
about 1/10 of the increase of the x10 gain. If the increase
does not increase in this ratio, the gain switch may be
defective.
ToxA
ToxB
x1
366
*364
48
