Senseair RDS R290

The Senseair Refrigerant Detection System R290 is a leak detection sensor module for HVAC applications using the low GWP refrigerant R290.

A protective housing, with a high-quality gas diffusion vent, protects the sensor element from dust and condense water droplets. Thanks to the built-in heating element, the Senseair RDS can operate in cold environments.


Using Modbus protocol, the measured data can digitally be transmitted to the control system.

A digital output signal is activated whenever the measured gas concentration reaches a configurable threshold. The output can alternatively be configured as a digital PWM signal or an analogue linear output reflecting the measured gas concentration.

  • Immunity to poisoning
  • Complies with 
    • UL 60335-2-40 ed.4
    • IEC 60335-2-40 ed.7
    • IEC 60079-29-1
  • High accuracy
  • High resolution
  • Fast response time
  • -40 – 70 °C operating temperature 
  • > 15 years expected lifetime
  • Maintenance-free

Target gas

R290, propane (C3H8) 1

Operating principle

Non-dispersive infrared (NDIR)

Measurement range

0─100 %LFL2


Standard range: ±2.5% LFL 2, 3

Extended range: ±5% LFL 2, 3

Response time

< 30s 4

Operating temperature*

-40─70°C 2

Storage temperature


Pressure dependence

1% reading per kPa deviation from normal pressure

Power supply options

24 ±10% VAC (009-3-0004 24V)

12 ±10% VDC (009-3-0005 12V)

  5 ±10% VDC (009-3-0006 5V) 6

Communication interface

Modbus over RS-485, 9600bps 5, 6


Digital signal (High/Low or PWM) or Analogue voltage or Analogue current. Digital High/Low is default factory setting. 6


5-pin (mates with Minitek® Pwr 3.0 10136653-05LF)


Maintenance free with Senseair ABC

Life expectancy

> 15 years


IEC 60335-2-40 Ed.7, UL 60335-2-40 Ed.4


Injection molded plastic, UL94V-0 rated


107 x 53 x 23mm


Note 1: Sensor measures molecules containing C-H bonds


Note 2: Standard range: 0–50% LFL and -30–60 °C

Extended range: 50–100% LFL and -40–70 °C


Note 3: After 3 ABC periods or 1 zero calibration and default

measurements settings


Note 4: When exposed to R290 with concentration 25% LFL or

higher, and Detection Threshold Limit Value set to 10% of LFL


Note 5: Configurable baud rate, range 9600 to 115.200bps


Note 6: 009-3-0006 5V is limited to UART communication and

digital output (no RS-485 and analogue outputs are available)

Product Product number

Senseair RDS R32 & R454 A/B/C

009-3-0001 24V

009-3-0002 12V

009-3-0003 5V

Senseair RDS R290

009-3-0004 24V

009-3-0005 12V

009-3-0006 5V