Precautions On Power Supply; Precautions On Installation - Ulvac G-TRAN Series Instruction Manual

Temperature fluctuation
Due to the measurement principle, the ambient temperature of the sensor unit of the
Pirani vacuum gauge affects the measurement value.
Pay attention to the installation position so that the ambient temperature does not
deviate significantly from the temperature during calibration (approx. 25℃).
Influence of electrons and ions
If there is a strong source of electrons or ions near the unit, it may not measure
the correct pressure. It also may damage this unit and cause a failure. Pay
attention to the installation location to avoid the influence of electrons and ions.
3.2.

Precautions on power supply

Power supply
This unit must be connected to a power supply or an evaluation unit that is ground-
protected and complies with the standard for PELV (EN/IEC 60204-1).
Also, install this unit with a fuse to connect. If the voltage supplied to this
unit is less than DC20V, it will not indicate the accurate pressure.
The voltage drop of the power cable
The voltage drop of the power cable may cause the voltage supplied to this unit to
fall under DC20V. Please note that the voltage drop may occur, especially when the
cable thickness is thinner than AWG24.
Recommended cable length when DC power supply voltage is DC24V, and the ambient
temperature is 20℃: AWG26: 10m, AWG24: 20m, AWG22: 30m
3.3.

Precautions on installation

Fixing method
Fix the cable so that no force is applied to the cable connection part.
Insert the unit cable securely and tighten the connector fixing screws firmly.
Life of female connector
The female connector used in the fitting part with this unit's sensor unit has a
life span. Poor contact of the connector will significantly shorten the sensor's
life, so try to avoid inserting and removing the connector as often as possible.
Make sure to tighten the sensor fixing screws firmly to prevent excessive force to
the connector.
Gas flow in the measurement system
The static pressure at the position where the sensor is connected is measured for
the pressure. Ensure that the sensor unit mounting opening is parallel to the gas
flow. In particular, do not allow gas to enter the sensor unit in the form of a
beam. Also, install the sensor unit to avoid the influence of the outgas.
Vibration
As the filament of the pirani sensor is as thin as φ25μm, avoid using it in a
place with a lot of vibration. Since the mechanical shock is the most common cause
of filament breakage, be careful when installing and handling it.
Outgas
Use an O-ring that outgases little to install the sensor unit. Using materials that
emit a lot of gas, such as a rubber tube or grease, to connect the sensor unit may
cause errors and shorten the product life.
10