FA 500 Dew Point Sensor with Programmable alarm

We aim to respond within 1 hour

Local display
Alarm output options
Working temperature range from -80 to 20 °Ctd

The FA 500 from CS instruments is a dew point sensor with a working temperature range of -80 to 20 °Ctd. Devices feature a 4 – 20 mA analogue output for the dew point along with a programmable alarm relay to act as a low or high threshold alarm.

Modbus-RTU interface over 485 is also available offering additional digital process outputs.

The integrated display allows for easy programming of process parameters, alarm threshold or output scaling.

The latest sensor technology offers extremely stable readings in the long term and offers a quick adaption time.

Different versions of the FA 500 are available dependant on dew point application.

Refrigeration dryers

For refrigeration dryers the working temperature range is -20 to +50 °Ctd.

Adsorption dryers

For adsorption dryers the temperature range is available as either -80 to +20 °Ctd or -60 to +30 °Ctd.

Accuracy of the sensor is stated as ± 1 °C at +50…-20 °Ctd, ± 2 °C at -20…-50 °Ctd and ± 3 °C at -50…-80 °Ctd.

Output data

Devices with Modbus-RTU also offer additional data via the digital interface which includes:

Pressure dew point [°Ctd.]
Temperature [°C]
Rel. humidity [% RH]
Abs. humidity [g/m³]
Degree of humidity [g/kg]
Moisture content V/V [ppmV/V]
Partial vapour pressure [hPa]
Atmospheric dew point [°Ctd.atm]

Key specifications

Measuring ranges	-80…20 °Ctd, -60…30 °Ctd,-20…50 °Ctd, or 0…100% RH
Accuracy	± 1 °C at 50…-20 °Ctd ± 2 °C at -20…-50 °Ctd ± 3 °C at -50…-80 °Ctd
Pressure range	-1…50 bar Special version up to 500 bar
Power supply	24 VDC (10…36 VDC)
Protection class	IP65
EMC	In acc. with DIN EN 61326-1
Operating temperature	-20…50 °C
Connection	x M12, 5-pin for analogue output, Modbus-RTU and alarm output, M-Bus (optional)Ethernet (PoE) (optional)
PC connection	Modbus-RTU interface (RS 485)
Output 3-wire	4…20 mA = -80…20 °Ctd 4…20 mA = -60…30 °Ctd 4…20 mA = -20…50 °Ctd
Burden for analogue outputs:	< 500 Ω
Alarm relay	NC, max. 60 VDC, 0.5 A
Screw-in thread	G 1/2″
Dimensions housing	6.5 x 85 x 75 mm (WxHxD)