Technical Specifications​

Measuring range: 1×10⁻⁴ Torr to 1000 Torr for air or nitrogen.

Alternative ranges: 1×10⁻⁴ to 1300 mbar, 1×10⁻² Pa to 130 kPa.

Resolution: 1×10⁻⁴ Torr, 1×10⁻⁴ mbar, 1×10⁻² Pa.

Analog output: nonlinear 0.375 VDC to 5.659 VDC, corresponding to 0 to 1000 Torr.

Setpoint: one SPDT relay, potentiometer adjusted.

Setpoint contact rating: 1 A at 30 VDC resistive, non-inductive AC per single-setpoint analog style; verify relay option for higher load.

Power supply: 11.5 VDC to 26.5 VDC, 1.6 W maximum.

Connector: 9-pin D-sub male.

Vacuum flange: NW16 KF.

Internal volume: 40 cc.

Installation orientation: horizontal preferred, especially above 1 Torr.

Operating temperature: 0°C to 40°C, non-condensing.

Storage temperature: -40°C to 70°C.

Maximum bakeout: 150°C non-operating with electronics removed.

Ingress protection: IP20 for electronic housing.

Functional Features​

Single analog pressure signal for PLC or controller input.

One relay setpoint for vacuum interlock, pump sequencing, or alarm.

Wide-range convection plus conduction compensation for stable atmospheric-to-high-vacuum reading.

Onboard temperature compensation and sensor-fault detection on supported variants.

Direct replacement within 275 analog relay family using the same NW16 KF interface.

Material Composition and Structure​

Electronic housing is aluminum extrusion with aluminum end plates. Sensor envelope uses 304 stainless steel, borosilicate glass, Kovar, alumina, nickel-iron alloy, and polyimide. Sensor wire is gold-plated tungsten or platinum depending on configured variant. Flange and fittings are stainless or aluminum-compatible vacuum materials.

Working Principle​

A heated wire loses heat to surrounding gas through conduction and convection. At low pressure conduction dominates; at higher pressure convection increases heat loss. The module measures wire temperature or bridge imbalance, converts it to pressure through a calibrated nonlinear curve, outputs proportional analog voltage, and compares pressure against the setpoint potentiometer to switch the relay.

Installation Requirements​

Mount the module electronically in a clean control area and connect the sensor head to the NW16 KF port using proper vacuum gasket. Keep the gauge axis horizontal for accurate reading above 1 Torr. Use the 9-pin D-sub with shielded cable, supply 11.5 VDC to 26.5 VDC, and ground the shield at the controller end. Do not power the sensor while the flange is open to atmosphere for extended periods unless the application requires it.

Usage Notes​

Perform zero verification periodically below 1×10⁻⁵ Torr if operating near 1×10⁻⁴ Torr. Remove electronics before bakeout above ambient limits. Avoid contaminant or oily process gas exposure that can coat the sensor wire. Replace the sensor element separately if filament fault is reported rather than replacing the full module.