Series 905
Page 9
Design Guide
Getting started with the 905 MicroPirani™ Sensor Kit
This guide describes how to install and operate the MicroPirani™ Sensor Kit with the evaluation board. For
a complete description of how to integrate the 905 in a system see the next chapters.
Please read the guide carefully, and note the following:
Make sure power is disconnected before connecting the MicroPirani™ sensor. Otherwise the
MicroPirani™ sensor element will be destroyed. Also, don’t measure the resistors on the sensor
as they will be destroyed by a regular ohmmeter.
Be careful when handling the MicroPirani™ sensor. Never touch the surface of the sensor itself
because the bonding wires are easily damaged.
Installing the electronics module
Unpack the evaluation board and the electronics module. Insert the flexible flat cable into the connector
(marked ‘K2’ on figure 4) on the electronics module, lock it tight, and position the module with the notch
facing the edge of the evaluation board. Gently insert the module into the socket, making sure not to bend
the pins.
Note:
The flexible flat cable can be inserted every way possible (both on the electronics module and/or the
sensor board). This has been done to ensure that a correct connection is established regardless of the way
the cable is mounted, which allows total freedom when connecting the sensor to the electronics.
Connecting the electronics module with the sensor
With the power disconnected, insert the flexible flat cable into the connector (marked ‘K1’ on figure 5) on
the sensor board and lock it tight. Mount the KF16 flange on your vacuum system.
Read the chapter “MicroPirani™ electrical connections” for information on how to use the sensor screw
terminals (S.Pin1-3).
Choosing communication standard
Choosing RS232 or RS485 communication is easily done using the jumpers on the evaluation board. There
are three separate jumpers next to the DSUB connector, and these should be in position 1-2 (all three) when
using RS232 and 2-3 (all three) when using RS485:
Note 1:
It is not necessary to power off the system in order to change communication standard.
Note 2:
Make sure, that the RxD and TxD jumpers are set to ‘Int’. If they are set to ‘Ext’ the communication
doesn’t go through the DSUB connector.
Connecting the communication cable
Connect a suitable cable to the evaluation board and a host system of your choice (don’t turn on the
PDR900 or plug in the power supply at this time). The PDR900 is capable of changing all user commands on
the 905. A standard terminal program can also be used to communicate with the 905 directly.
