The Model 531 Thermocouple Vacuum Gauge provides continuous and accurate indication of total pressure from 1 x 10-3 to 2 Torr absolute. Developed to combine rugged dependability and outstanding performance, the 531 offers fast response and low power drain.
Principles of Operation
Thermocouple gauges measure pressure in terms of the amount of heat that gas will conduct away from a hot wire. The sensing element is a combination heater and thermocouple. Cross-shaped, it is formed by joining two short resistance wires of different compositions, a method of construction which gives excellent shock resistance and yet provides the minimum mass required for fast response. With a fixed heater power, the temperature of the junction, which depends on the conductivity of the gas, is indicated by the voltage output of the thermocouple. As the pressure drops, the thermocouple gets hotter and its output increases. Readout is accomplished on a millivolt meter calibrated to indicate pressure.
Identical to the Agilent/Varian F0472301 and Thermo/Finnigan #00105-02000.
|Filament Current||165 mA (gives 14 mV across the thermocouple at pressures below 10 -3 Torr)|
|Response Time||3 sec. (10 -3 to 1.0 Torr)|
|Range||1 x 10 -3 to 2 Torr|
|Output||0 to 14mV|
|Heater Resistance||1.4 ohms (approx.)|
|Dimensions||1.21" O.D. x 3" long|
|Connections||May be soldered into a system, used with 1/2" '0' ring compression seal or threaded on 1/8" MNPT fitting.|
|Cable Connection||Octal Base (std.)|
|Casing||Nickel-plated mild steel|
|Pins||Nickel-iron alloy (Ni 48%, Fe 52%)|
- Varian Thermocouple Vacuum Gauge Controls - 800 Series The 800 Series Thermocouple Vacuum Gauge Controls are used for repeatable, stable pressure measurement in the 10 -3 Torr to 2 Torr range.