Thermo Scientific 42i Instruction Manual page 217

Thermo Fisher Scientific
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 ground antistatic wrist strap must
be worn while handling any internal component.
Note An error in the zero setting of the pressure transducer does not
introduce a measurable error in the output concentration reading.
Therefore, if only a barometer is available and not a vacuum pump, only
adjust the span setting.
A rough check of the pressure accuracy can be made by obtaining the
current barometric pressure from the local weather station or airport and
comparing it to the pressure reading. However, since these pressures are
usually corrected to sea level, it may be necessary to correct the reading to
local pressure by subtracting 0.027 mmHg per foot of altitude.
Do not try to calibrate the pressure transducer unless the pressure is known
accurately. ▲
1. Remove the cover.
2. Disconnect the tubing from the pressure transducer and connect a
vacuum pump known to produce a vacuum less than 1 mm Hg.
3. From the Main Menu, press
to scroll to Pressure Calibration > and press
The Pressure Sensor Cal menu appears.
Note If Service Mode is not displayed, refer to
Mode" on page 7-4 , then return to the beginning of this step.
4. At the Pressure Sensor Cal menu, press
The Calibrate Pressure Zero screen appears.
5. Wait at least 10 seconds for the zero reading to stabilize, then press
to save the zero pressure value.
▲
to scroll to Service > press
Servicing
Pressure Transducer Calibration
▲
▲
.
"Accessing the Service
▲
to select Zero.
Model 42i Instruction Manual
>
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