Dual Bar Graph
from of 1 m torr to 5000 m torr
station has a relay output adjustable from the front
panel LED for relay output status
mountable or beach top use
the rugged and proven GTC-036 senor
The GTC-390 thermocouple vacuum gauge is a dual station thermal
conductivity type gauge and controller housed in a DIN-style case.
The unit uses the rugged and proven GTC-036 sensor and covers
a pressure range of 1 mtorr to 5000 mtorr. Pressures are displayed
simultaneously for both stations on two 40-segment bar graph displays.
Each station includes a relay set point that can be set within
the range of the gauge. The relay set point for each station may
be viewed by pressing the “View” buttons on the front
panel. Adjusting the set points is accomplished by turning the
front panel potentiometers marked “Set”. An LED indicator
displays the output status of each relay control output.
Principal of Operation
The GTC-390 thermocouple gauge consists of two identical pressure
measurement and control circuits that function as follows: A constant
current source is supplied to the heating element of the GTC-036
sensor. The thermocouple junction in the sensor generates a voltage
signal that varies with the temperature of this heating element.
A decrease in pressure reduces the number of gas molecules available
to transfer heat away from the heating element, resulting in a
temperature rise and an increased output from the sensor. This
small voltage signal is filtered, amplified, and inverted resulting
in a signal with a span of several volts that is proportional
to pressure. This pressure signal is then passed through a signal
selection circuit to the display drivers where it is compared
to a high and a low reference and the proper display segments
are illuminated. A voltage comparator is used to activate the
set point relay as well as the front panel set point indicator.
There is a small amount of hysteresis built into this circuit.
The “View” button causes the signal selection circuit
to send the pressure set point level to the display drivers rather
than the pressure.
VAC 50/60 Hz 40 watts
or 9 VDC 9 watts
mtorr to 5000 mtorr on a 40-segment bar-graph
of Sensing Stations
GTC-036 with 1/8” pipe thread or 0.406” diameter
O-Ring sealing surface.
ft length standard with both 9-pin gauge and octal sensor
wide 5.10” deep
wide x 2.68” high (allow 8” for mounting depth)
removable three position terminal block for each station with
common, normally closed, normally open connections
Trip Point Adjustment
mtorr to 5000 mtorr
5 Amp 250 VAC Max
information for the components mentioned on this page is listed
din panel mount, dual 40 segment bar graph display, with single
set point, pressure scale of 0-5 torr with cables, less sensors
above - complete with two GTC036 sensors
change the combination for ordering the first dash number is always
–0 the second dash indicates the number of station cable
(zero, one or two), the third dash number determines the length
of the connector cable, -0010 = 10’ connector cable, -0020
= 15’ connector cable, -0030 =25’ connector cable,
-0040 =50’ connector cable and the fourth dash number indicates
the number of sensors (zero, one or two).