Chapter Four: Operation
How To Set the Trip Points on Type 623H
39
How To Set the Trip Points on Type 623H
There are two trip points, labeled as Trip Point A and Trip Point B, on the 623H transducer, each
with its own trip point adjustment. The voltage for Trip Point A can be measured with a
voltmeter across pins 1 (on TB2) and pin 2 (on TB1). The voltage for Trip Point B can be
measured across pin 8 (on TB2) and pin 2 (on TB1).
Figure 10: How To Measure the Trip Point Voltage for Type 623H
To adjust a trip point, turn the appropriate trip point adjustment screw (refer to Figure 8, page 37)
until the voltage displayed on the voltmeter equals the voltage of the pressure output signal at the
desired trip point level.
For example, if at the desired trip point pressure the output signal is 8 Volts, turn the appropriate
trip point adjustment screw until the voltmeter reads 8 Volts. If you want an output signal of 8
Volts at the trip point, turn the appropriate trip point adjustment screw until the voltmeter reads 8
Volts.
Note
Due to hysteresis, the actual relay trip point pressure may be slightly
higher than the pressure for which the trip point was set. The difference
between the
set
trip point pressure and the
actual
trip point pressure will
vary depending upon the degree of hysteresis you have selected.
Note
The electromechanical trip point relays in this product are fit for general
purpose applications. If the manometer is intended for use in high cycle
count applications including, but not limited to, Atomic Layer Deposition,
please consult your local office for advice on more appropriate available
MKS solutions.
Refer to
Hysteresis
, page 37, and
How To Adjust the Trip Point Hysteresis
, page 44, for more
information.
8
TB2
Measure the voltage
for Trip Point A
across these pins
Measure the voltage
for Trip Point B
across these pins
5
TB1
1
1
Cha
s
s
is
