Teledyne T100 Manuale Utente

Measure the voltage across test points TP1 and TP4. With the sample pump 
disconnected or turned off, this voltage should be 4500 

 250 mV. With the pump 

running, it should be about 0.2 V less as the sample pressure drops by about 1 in-Hg-A 
from ambient pressure. If this voltage is significantly different, the pressure transducer 
S2 or the board may be faulty. A leak in the sample system to vacuum may also cause 
this voltage to be between about 0.6 and 4.5. Ensure that the front panel reading of the 
sample pressure is at about 1 in-Hg-A less than ambient pressure. 

The zero/span valves and IZS options need to be enabled in the software (contact the 
factory on how to do this). Refer to Figure 3-19 and Figure 3-20 for a flow diagram with 
zero/span valve or IZS option. 

  Check for the physical presence of the valves or the IZS option. 
  Check that a working perm-tube is installed in the IZS oven assembly. 
  Check front panel for correct software configuration. When the instrument is in 

SAMPLE mode, the front panel display should show CALS and CALZ buttons in 
the second line of the display. The presence of the buttons indicates that the option 
has been enabled in software. In addition, the IZS option is enabled if the TEST 
functions show a parameter named IZS TEMP. 

The IZS option is heated with a proportional heater circuit and the temperature is 
maintained at 50° C ±1°. Check the IZS TEMP function via front panel display (refer to 
Section  4.1.1) and the IZS_TEMP signal voltage using the SIGNAL I/O function 
under the DIAG Menu (refer to Section 5.9.1).  

At 50°

 

C, the temperature signal from the IZS thermistor should be around 2500 mV. 

The box temperature sensor (thermistor) is mounted on the motherboard at the bottom, 
right corner of the CPU board when looking at it from the front. It cannot be 
disconnected to check its resistance. Box temperature will vary with, but will always 
read about 5° C higher than, ambient (room) temperature because of the internal heating 
zones sample chamber and other devices.  

To check the box temperature functionality, we recommend checking the BOX_TEMP 
signal voltage using the SIGNAL I/O function under the DIAG Menu (refer to Section 
5.9.1).  

At about 30°

 

C (5

 above typical room temperature), the signal should be around 1500 

mV. We recommend using a certified or calibrated external thermometer / temperature 
sensor to verify the accuracy of the box temperature.  

PMT temperature should be low and constant. It is more important that this temperature 
is maintained constant than it is to maintain it low. The PMT cooler uses a Peltier, 
thermo-electric element powered by 12 VDC from the switching power supply PS2. The 
temperature is controlled by a proportional temperature controller located on the 
preamplifier board. Voltages applied to the cooler element vary from +/- 0.1 to +/- 12 

06807C DCN6650