Using The Analog Output Test Channel; Table 9-3: Test Channel Outputs As Diagnostic Tools - Teledyne T700 Operation Manual

Troubleshooting and Service

9.2. USING THE ANALOG OUTPUT TEST CHANNEL

Table 9-3: Test Channel Outputs as Diagnostic Tools

TEST
DESCRIPTION
CHANNEL
NONE
The raw output of the
O3 PHOTO
photometer during its
MEAS
measure cycle
The raw output of the
O3 PHOTO
photometer during its
REF
reference cycle
The raw output of the
O3 GEN
O generator's
3
REF
reference detector
The pressure of gas in
SAMPLE
the photometer
PRESSURE
absorption tube
SAMPLE The gas flow rate
FLOW through the photometer
The temperature of gas
SAMPLE
in the photometer
TEMP
absorption tube
PHOTO
The temperature of the
LAMP
photometer UV lamp
TEMP
The temperature of the
O3 LAMP
O generator's UV
3
TEMP
lamp
The temperature inside
CHASSIS
the T700's chassis
TEMP
(same as BOX TEMP)
The current
O3 PHOTO concentration of O
CONC
being measured by the
photometer.
248
The signals available for output over the T700's analog output channel can also be used
as diagnostic tools. See Section 4.7 for instruction on activating the analog output and
selecting a function.
ZERO
TEST CHANNEL IS TURNED OFF
0 mV 5000 mV*
0 mV
0 mV
0 "Hg 40 "Hg-In-A
3
0 cm /min 1000 cm
0 C
0 C
0 mV
0 C
3
- - -
Teledyne API – Model T700 Dynamic Dilution Calibrator
FULL
SCALE
If the value displayed is:
- >5000 mV: The UV source has become brighter; adjust the
UV Detector Gain potentiometer.
- < 100mV – Bad UV lamp or UV lamp power supply.
- < 2500mV – Lamp output has dropped, adjust UV Preamp
Board or replace lamp.
If the value displayed is constantly changing:
- Bad UV lamp.
- Defective UV lamp power supply.
- Failed I 2
C Bus.
5000 mV
If the PHOTO REFERENCE value changes by more than
10mV between zero and span gas:
- Defective/leaking M/R switching valve.
Possible causes of faults are the same as O3 GEN REFERENCE
5000 mV
WARNING from Table 9-1.
Check for Gas Flow problems.
3
/m Check for Gas Flow problems.
Possible causes of faults are the same as PHOTO STEMP from
70 C
Table 9-2.
Possible failure of:
- Bench lamp heater
- Bench lamp temperature sensor
- Relay controlling the bench heater
70 C
- Entire Relay PCA
- I 2
C Bus
- Hot Lamp
5000 mV Same as PHOTO LAMP TEMP WARNING from Table 9-1.
Possible causes of faults are the same as BOX TEMP from Table
70 C
9-2.
- I 2
C Bus malfunction
- Gas flow problem through the photometer.
- Electronic failure of the photometer subsystems.
- Failure or pressure / temperature sensors associated with the
photometer.
- Bad/incorrect Span Gas concentration.
- Contamination of the Zero Air supply.
- Malfunction of the O
- Internal A/D converter problem.
CAUSES OF EXTREMELY
HIGH / LOW READINGS
generator.
3
06873B DCN6388