10.1.2. Fault Diagnosis with Test Functions

TROUBLESHOOTING & REPAIR

M102E/M501 TRS

 

(Addendum to M101E Manual - P/N 04740 Rev A)

10.1.2. Fault Diagnosis with Test Functions

The Following table supercedes Table 11.2 of the M101E Manual - P/N 04740 Rev A.

Table 10-2: Test Functions - Possible Causes for Out-Of-Range Values

TEST

NOMINAL

POSSIBLE CAUSE(S)

FUNCTION

VALUE(S)

 

 

 

 

 

1 ppb with zero

Faults that cause high stability values are: pneumatic leak; low or very unstable

STABIL

UV lamp output; light leak; faulty HVPS; defective preamp board; aging PMT; PMT

air

 

recently exposed to room light; dirty/contaminated reaction cell.

 

 

 

 

 

SAMPLE FL

650 cm3/min

Faults can be caused by: clogged critical flow orifice; pneumatic leak; faulty flow

± 10%

sensor; sample line flow restriction.

 

 

 

 

 

 

High or noisy readings could be due to: calibration error; pneumatic leak; light

 

 

leak (improper assembly); aging UV filter; low UV reference output; PMT recently

PMT

-20 TO 150 mV

exposed to room light; light leak in reaction cell; reaction cell contaminated; HVPS

with zero air

problem.

 

 

 

It takes 24-48 hours for a PMT exposed to ambient light levels to return to normal

 

 

functioning.

 

 

 

 

 

Noisy Norm PMT value (assuming unchanging SO2 concentration of sample gas):

NORM PMT

- -

Calibration error; HVPS problem; PMT problem; UV reference problem; UV lamp

 

 

problem.

 

 

 

 

 

This is the instantaneous reading of the UV lamp intensity. Low UV lamp intensity

UV LAMP

2000 -4000 mV

could be due to: aging UV lamp; UV lamp position out of alignment; faulty lamp

transformer; aging or faulty UV detector; dirty optical components.

 

 

 

 

Intensity lower than 600 mV will cause UV LAMP WARNING.

 

 

 

 

 

The current output of the UV reference detector divided by the reading stored in

 

 

the CPU’s memory from the last time a UV Lamp calibration was performed. Out

LAMP RATIO

30 TO 120%

of range lamp ratio could be due to: malfunctioning UV lamp; UV lamp position

 

 

out of alignment; faulty lamp transformer; aging or faulty UV detector; dirty

 

 

optical components; pin holes or scratches in the UV optical filters; light leaks.

 

 

 

STR LGT

40-100 ppb

High stray light could be caused by: aging UV filter; contaminated reaction cell;

light leak; pneumatic leak.

 

 

 

 

 

DRK PMT

-50 - +200 mV

High dark PMT reading could be due to: light leak; shutter not closing

completely; high pmt temperature; high electronic offset.

 

 

 

 

 

DRK LMP

-50 - +200 mV

High dark UV detector could be caused by: light leak; shutter not closing

completely; high electronic offset.

 

 

 

 

 

HVPS

400 V to 900 V

Incorrect HVPS reading could be caused by; HVPS broken; preamp board circuit

problems.

 

 

 

 

 

RCELL TEMP

50ºC ± 1ºC

Incorrect temperature reading could be caused by: malfunctioning heater; relay

board communication (I1C bus); relay burnt out

BOX TEMP

ambient

Incorrect temperature reading could be caused by: Environment out of

+ ~ 5ºC

temperature operating range; broken thermistor; runaway heater

 

 

 

 

PMT TEMP

7ºC ± 2ºC

Incorrect temperature reading could be caused by: TEC cooling circuit broken;

constant

High chassis temperature; 12V power supply

 

 

 

 

IZS TEMP

50ºC ± 1ºC

Malfunctioning heater; relay board communication (I1C bus); relay burnt out

(OPTION)

 

 

 

ambient

Incorrect SAMPLE pressure could be due to: pneumatic leak; malfunctioning

PRESS

valve; malfunctioning pump; clogged flow orifices; sample inlet overpressure;

± 2 IN-HG-A

 

faulty pressure sensor

 

 

 

 

 

SLOPE

1.0 ± 0.3

Slope out of range could be due to: poor calibration quality ; span gas

concentration incorrect; leaks; UV Lamp output decay.

 

 

 

 

 

 

 

High offset could be due to: incorrect span gas concentration/contaminated zero

OFFSET

< 250 mV

air/leak; low-level calibration off; light leak; aging UV filter; contaminated

 

 

reaction cell; pneumatic leak.

 

 

 

TIME OF DAY

Current time

Incorrect Time could be caused by: Internal clock drifting; move across time

zones; daylight savings time?

 

 

 

 

 

52

05514 Rev A1

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Teledyne manual Fault Diagnosis with Test Functions, M102E/M501 TRS, Troubleshooting & Repair, Rev A1, functioning