Teledyne T100 Manuale Utente

the supply. The second is the programming voltage which is generated on the Preamp 
Board. This power supply is unlike a traditional PMT HVPS. It is like having 10 
independent power supplies, one to each pin of the PMT. The test procedure below 
allows you to test each supply. 

1. Check the HVPS test function via the front panel and record the reading level. 

Adjustment of the HVPS output level is covered in the hardware calibration 
procedure in Section 12.7.2.8.  

2.  Turn off the instrument. 

3.  Remove the cover and disconnect the 2 connectors at the front of the PMT housing. 

4.  Remove the end plate from the PMT housing. 

5.  Remove the HVPS/PMT assembly from the cold block inside the sensor.  Un-plug 

the PMT. 

6.  Re-connect the 7 pin connector to the Sensor end cap, and power-up the 

instrument. 

7.  Check the voltages between the pairs of pins listed in Table 12-9.  The result for 

each pair should be equal and approximately 10% of the reading level recorded in 
Step 1.   

 If HVPS reading = 700 VDC 

1  2 

70 VDC 

2  3 

70 VDC 

3  4 

70 VDC 

4  5 

70 VDC 

5  6 

70 VDC 

6  7 

70 VDC 

7  8 

70 VDC 

 

8.  Turn off the instrument power, and re-connect the PMT tube, and then re-assemble 

the sensor. 

If any faults are found in the test, the HVPS must be replaced.  There are no user 
serviceable parts inside the HVPS. 

The pressure/flow sensor circuit board, located behind the sensor assembly, can be 
checked with a voltmeter using the following procedure, which assumes that the wiring 
is intact and that the motherboard and the power supplies are operating properly. 

  Measure the voltage across TP1 and TP2, it should be 10.0  0.25 V. If not, the 

board may be faulty.  

  Measure the voltage across capacitor C2; it should be 5.0 ± 0.25 V. If not, the board 

may be faulty. 

06807C DCN6650