MKS Baratron 223B, Instruction Manual, Page: 16 / 31

Setup Chapter Two: Installation
8
Mounting Instructions
The Type 223 may be mounted in any attitude, although a horizontal tube axis is recommended.
If vibrations are anticipated, it is recommended that the plane of the diaphragm (flat surface of
the sensor) be oriented parallel with the major oscillating axis. Any fittings may be used on the
3
/
16
” O.D. tubing, although maximum O.D. of the fittings should be selected to clear the terminal
block cutout in the cover, as removal of the cover over the fitting is necessary for service.
Electrical Connections and Cables
Electrical connections are made to the terminal block as marked on the cover. Both the power
supply common (P COM) and the signal common (S COM) are connected together inside the
Type 223 unit. The output signal is the voltage between the S COMMON and PRESSURE OUT
terminals.
Use cable CB112-2 to connect the 223 transducer to MKS supplied readouts, such as the type
146, 651, 652, or 660 units. Use cable CB473-1 to connect the 223 transducer to MKS digital
type readouts, such as the type PDR-C-1C/2C, PDR-5B, or the PDR-D-1 units.
Connections are made according to Table 1.
Cable Connections
Type 223 Cable Wire Color MKS Readout Connection
+ 15 Green + 15
- 15 White - 15
COMMON Black (small) (paired with green)
Black (small) (paired with red)
P COM
S COM
PRESSURE OUT RED PRESSURE IN
No Connection Black (heavy) CHASSIS
Table 1: Cable Connections
Even though the 223 output signal has the same common terminal as the power supply, it is still
best to use a differential input readout. Appropriate connections are shown in Figure 2, page 9,
for applications where a customer supplied readout and power supply are used. Note there are
two wires connected to the 223 P COMMON terminal. One is power common from the power
supply. One is signal low to the readout. The third is the power common of the readout which
keeps the differential inputs biased properly. Often, but not always, this readout power common
is the shield of the signal wires.