The GT 340A is an electrically powered gauge for use in harsh environments. The rugged electronics are designed for longevity and occasional accidental misuse. Two analog scales allow the user to take vacuum measurements from atmosphere to 1×10-3 torr. A separate meter scale for the 1 to 100 millitorr range provides increased readability in this critical area. Meter scales are calibrated in dry air.
- Measures from atm to 1×10-3 torr
- Rugged thermisitor sensor – excellent for high vapor applications
- Interchangeable pre-calibrated tubes
- Rugged circuitry for high reliability
- Two scales for accurate pressure reading
- External circuit control feature available
- Leak detect capability on STA.1
- Second station can be added on-site
- Analog meter indicates direction of pressure change
- 115/230V, 50/60 Hz operation
Principle of Operation
A single element is employed in a bridge-type detector driven from a constant regulated voltage source. The inverse resistive characteristics of the sensor unbalances the bridge as pressure changes occur, thereby causing a current change. A microammeter scaled in pressure units measures this current.
Gauge has Leak Detect Mode. Front panel switch allows adjustment of the gauge sensitivity to aid vacuum leak detection.
Connections on the rear panel of the gauge cabinet provide a pressure-responsive output independent of the selector switch. A 10-, 50-, or 100-millivolt high-impedance recorder with suitable attenuating network can be connected here to cover the entire pressure range of the gauge at either sensing station.
Two GT-340A two-station gauges can be mounted side-by-side for applications requiring four-station operation, with the added advantages of two read-out meters and redundant circuitry. Two GT-340A two-station gauges can be mounted side-by-side for applications requiring four-station operation, with the added advantages of two read-out meters and redundant circuitry.
Width: GT-340A, 4″
Depth: GT-340A, 6-1/2″
Height: GT-340A, 6″
Net Weight: GT-340A, 6 lbs.
Number of Stations: 1 or 2
Type of Mounting: Bench or panel
Normal Operating Temperature Range: 15 to 35ºC
AC Power Input: 115/230 volts, 50/60 Hertz
Meter Scale Ranges: 0 to 100 milliTorr; 0 to atmosphere
Recorder Output: 0 – 2.5 volts
Envelope w/baffle housing length including base: 2-9/16″
Envelope O.D.: 1-1/4″
Tubulation Material: Nickel-plated steel
Tubulation Length: 1-3/8″
Tubulation O.D.: 0.405″ diameter sealing surface and 1/8″ pipe thread
Thermistor Element Operating Temperature: 90ºC
Maximum Bakeout Temperature of Sensor Envelope: 100ºC
Pressure Range: High Vacuum to 60 psig
Ordering information for the components mentioned on this page is listed below.
Gauge Type & Number of Stations
GT-340A-1: Thermistor gauge, single-station, Part number 5506330-1
GT-340A-2: Thermistor gauge, two-station, Part number 5506330-2
GT-034 – Thermistor gauge sensor – Part Number 277289
Vacuum Port Adapters
- KF-16 to 1/8″ FPT KF – Part Number 500230-16
- KF-25 to 1/8″ FPT – Part Number 500230-25
- KF-40 to 1/8″ FPT – Part Number 500230-40
- KF-50 to 1/8″ FPT – Part Number 500230-50
- CF-16 to 1/8″ FPT – Part Number 500231-1
- CF-35 to 1/8″ FPT – Part Number 500231-2
- 1″ hole mount to 1/8″ FPT – Part Number 500236
Cable 10′ standard – Station 1, Part number 5505863-1
Cable 10′ standard – Station 2, Part number 5505889-1
Cable 15′ standard – Station 1, Part number 5505863-2
Cable 15′ standard – Station 2, Part number 5505889-2
Cable 25′ standard – Station 1, Part number 5505863-3
Cable 25′ standard – Station 2, Part number 5505889-3
Cable 50′ standard – Station 1, Part number 5505863-4
Cable 50′ standard – Station 2, Part number 5505889-4