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Ambient Temperature
Calibration
Thermo Fisher Scientific
12. Tighten the locknut on the back pressure regulator and set the lock on
the pressure adjust knob on the output pressure regulator.
Use the following procedure to calibrate the ambient internal temperature
for the instrument.
Equipment Required:
Calibrated thermometer or 10K ±1% resistor
WARNING The service procedures in this manual are restricted to qualified
service representatives.
If the equipment is operated in a manner not specified by the manufacturer,
the protection provided by the equipment may be impaired.
Equipment Damage Some internal components can be damaged by small
amounts of static electricity. A properly grounded antistatic wrist strap must
be worn while handling any internal component.
1. Remove the instrument cover.
2. Tape the thermistor
Note Since the thermistors are interchangeable to an accuracy of ±0.2 °C,
and have a value of 10K ohms at 25 °C, an alternate procedure is to connect
an accurately known 10K resistor to the thermistor input (AMB TEMP) on
the measurement interface board, and enter the temperature reading.
A 1 °C change corresponds to a ±5% change in resistance, thus this
alternative procedure can be quite accurate as a check; however, it clearly is
not NIST traceable.
3. From the Main Menu, press
to scroll to Temperature Calibration, and press
The Calibrate Ambient Temperature screen appears.
(Figure
7-3) to a calibrated thermometer.
to scroll to Service, press
Servicing
Ambient Temperature Calibration
.
Model 146i Instruction Manual
>
7-53
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