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Residual Pressure Transducer LFM208

The residual pressure transducer is a device used to detect the air pressure of the fire exit. Usually, the air pressure of the fire exit needs to be higher than other rooms and areas to prevent the smoke and harmful gas from overflowing into the fire exit. When the pressure value of the device is lower than the normal value, it means that there is a safety hazard risk in this fire passage.


* CQC certificated

* For fire fighting system Application

Specification of Residual Pressure Transducer LFM208

Measurementrange 0~±100Pa
Accuracy (a)±1%F.S
Working temperature(-20℃~75℃
Compensated temperature(-5℃~60℃
Protection GradeIP30
Power Supply24VDC±2.4V
Trachea connection(+)High voltage side,(-)Low pressure side; adopt 3.5mm inner diameter hose
InstructionsGreen status, red alarm indicator
Display methodWith display/without display
Measured mediumAir and non-corrosive gas
Control signal(b)switching value
Communication modeTwo bus (two-wire system)/RS-485 (four-wire system)
Withstand voltage1000Pa

a) Accuracy is obtained by testing at room temperature 25℃; b) Connecting resistive load (optional)

How to Select

Code and description






Measurement range




without display

Screen display





Communication mode


P=Pb Two -bus





Model selection example

Note: For example, when LFM208-4050-DR is selected, the operating pressure of the residual pressure transmitter is 50Pa. The reset pressure is 40Pa. With screen display, RS485 communication output.

Function Description

The residual pressure transmitter panel has two indicators: a green status indicator and a pressure alarm indicator;

1. Status indicator: Under normal working condition, the green indicator light is on; under the equipment failure condition, the green indicator light flashes;

2. Alarm indicator: During pressure measurement, when the air pressure is lower than the reset pressure, the alarm light is always on. If the air pressure is higher than the operating pressure. The alarm light flashes. When the pressure is between the reset pressure and the operating pressure, the alarm light is off;

If the product has a pressure display window, the pressure value can be directly displayed;

LEFOO Function Description LFM208

Features of Residual Pressure Transducer LFM208

  • Adopt American imported pressure sensing element

  • Elevator front room and staircase of high-rise building

  • Basement and refuge

  • Pressure monitoring in hotels, shopping malls, hospitals and

  • other public places

  • Compliant with The National Standard

    《Technical Standard for Smoke Management System in Buildings》

Applications of Residual Pressure Transducer LFM208

Pressure monitoring for fire exits. And prevent the leakage of toxic gases and dense smoke when fire broke out.

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