946 Controller Instruction Manual
pg. 72
electronics module on the cable connector may help to prevent loss or interchange of the module on
reassembly.
7.4 Installing Capacitance Manometers - MKS Baratron
The Series 946 Controller supports a number of Capacitance Manometers, including the MKS unheated
Baratrons and MKS 45 C heated Baratrons. They are available in full scale ranges from 0.02 to 10,000
Torr, each with a 3-decade range. A CM module operates up to two Capacitance Manometers, and the
total combined current requirement of operating sensor(s) must be 1 amp or less.
See an MKS Baratron instruction manual for complete information on using these capacitance
manometers.
The Series 946 Controller also supports the gas-independent Series 902B Piezo resistive gauges. Refer
to Section 7.5 for information on this.
Do not connect heated Baratrons with controlled temperatures higher than 45
o
C. It
may damage the Capacitance Manometer
.
7.4.1 Installing a Capacitance Manometer
In general Capacitance Manometers may be mounted in any position although the most sensitive units
(i.e. those with the lowest full scale value) may require a specific orientation to meet factory calibration
specifications. Please consult the information supplied with the Capacitance Manometer, However, it is
recommended that capacitance manometers in general be installed with the measuring port facing down
to allow contamination to fall away from the pressure sensing diaphragm. The sensor port will easily carry
the weight of the transducer.
Due to the failure of many users to follow the proper tightening procedures for
single or double metal ferrule compression vacuum fittings and the resulting damage to
the pressure sensor, MKS does not warrant this product when such fittings are used.
7.4.2 Connecting a Capacitance Manometer
A shielded cable with 9 pin male d-sub on the controller end and a 9 or 15 pin male d-sub end on the
Baratron end is required to connect the Baratron to the module on the controller. The pin-outs for the D-
Sub connectors on the CM cables is shown in Table 7-4. Part numbers of cables are given in the
Accessory Section of this manual.
Function
937B/946
Module
Connector Pin
Baratron (CM)
Connector Pin
(15 pin D-sub)
Baratron (CM)
Connector Pin
(9 pin D-sub)
-15 V
1
6
+15 V
5
7
4
Chassis Ground
6
Signal -
7
12
8
8
2
1
+/- 15V Return
9
5
9
Table 7-3 Pin Out of the 9 Pin D-sub Connector on CM Module.