GTC-390 Thermocouple
Dual Bar Graph
Features
- Dual
pressure display
- Measures
from of 1 m torr to 5000 m torr
- Each
station has a relay output adjustable from the front
panel
|
- Front
panel LED for relay output status
- Panel
mountable or beach top use
- Uses
the rugged and proven GTC-036 senor
|
Description
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.
Specifications
| GAUGE
SPECIFICATIONS GTC-390 |
| Power
Input |
100-120
VAC 50/60 Hz 40 watts
or 9 VDC 9 watts
|
| Pressure
Scales |
1
mtorr to 5000 mtorr on a 40-segment bar-graph |
| Number
of Sensing Stations |
1
or 2 |
| Pressure
Sensing Tube |
Type
GTC-036 with 1/8” pipe thread or 0.406” diameter
O-Ring sealing surface. |
| Tube
Cable |
10
ft length standard with both 9-pin gauge and octal sensor
connector |
| Cabinet
Dimensions |
5.67”
wide 5.10” deep
2.84” high |
| Mounting
Hole Dimensions |
5.45”
wide x 2.68” high (allow 8” for mounting depth) |
| Relay
Connections |
One
removable three position terminal block for each station with
common, normally closed, normally open connections |
| Relay
Trip Point Adjustment |
1
mtorr to 5000 mtorr |
| Relay
Types |
SPDT
5 Amp 250 VAC Max |
GTC-036
Tube Specifications
http://www.myers-vacuum.com/gtc036.shtml
Ordering
information for the components mentioned on this page is listed
below.
| ITEM
|
DESCRIPTION
|
P/N
|
| GTC-390 |
THERMOCOUPLE
din panel mount, dual 40 segment bar graph display, with single
set point, pressure scale of 0-5 torr with cables, less sensors |
500623-0210 |
| GTC-390 |
As
above - complete with two GTC036 sensors |
500623-0212 |
To
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).
|
Myers
Vacuum