S230 / S231

S230 / S231 Compressed Air Dew Point Transmitter for Ex Applications (-100… +20 °C Td / -50 … +20 °C Td)

Ex dew point sensors provide long-term stable dew point monitoring in industrial or hazardous applications.

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Industrial dew point transmitter for rough environment

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Unique QCM sensor for precise measurements

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Low dew point measurement down to -100 °C Td

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Compact and robust transmitter design

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Explosion proof for Ex-area applications

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Low maintenance costs due to stable measurements

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4 ... 20 mA (isolated); Modbus/ RTU

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Pressure -0.1 ... 1.6 MPa (S230); -0.1 ... 35 MPa (S231)

The SUTO S230 / S231 Heavy-Duty Dew Point Transmitters provide reliable, long-term stable dew point monitoring for compressed air and gases in harsh and hazardous applications. The fast response time ensures safe and reliable indication whenever dew points are out of valid ranges

S230 For Low Dew Point Applications

The S230 Dew Point Transmitter provides accurate results of a range down to -100 °C Td. This makes it perfectly suitable for special applications where a low dew point needs to be measured.

S231 for Standard Range Applications

S231 Dew Point Transmitter comes with a standard range from -50… +50 °C Td, offering a wide range of dew point monitoring applications for compressed air and gases.

Ex Areas Solution

The optional IECEx approval makes it the perfect tool to be used in explosive environment (Ex area). SUTO’s unique dual sensor technology optimizes sensor sensitivity and accuracy by automatically selecting the ideal sensor type for the situation.

User-Friendly Output Signals

The S230/S231 come ready to use and simple to install with your choice of 4-20mA or Modbus RTU (RS485) outputs. If required, parameters can be quickly monitored through the SUTO service software. The transmitters can also be connected the SUTO S331 (stationary) or S551 (portable) data logger and the data can be transferred for further analysis.

SUTO Exchange Service

The SUTO exchange calibration service helps to eliminate downtime and enables users to have a seamless record of their dew point measurements. Learn more about our advanced service here.

Should you have any special requests or need a further application consultation, please contact us here.

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  • Dew point measurement in explosive environments
  • Outdoor / all-weather flow applications
  • Explosive environments


Dew Point
Accuracy± 1 °C Td (0 ... 20 °C Td)
± 2 °C Td (-60 ... 0 °C Td)
± 3 °C (-100 ... -60 °C Td)
Selectable units°C, °F, bar(g), MPa(g), psi(g), % rH,
g/m³, mg/m³, G/m³ atm., mg/m³ atm., ppm(v), g/kg, °C Td atm.
Measuring range (model depending)S230: -100 ... +20 °C Td
S231: -50 ... +20 °C Td
SensorPolymer + QCM
Response time t90 (@ 4l/min)-20 °C Td -> -60 °C Td = < 240 s
-60 °C Td -> -20 °C Td = < 30 s
Accuracy0.3 °C
Measuring range-30 ... +70 °C
Reference conditions
Selectable conditionsPressure Dew Point,
Atmospheric Dew Point


Analog output
Signal4 ... 20 mA (isolated)
ScalingS230: 4 mA = -100 °C Td;
20 mA = +20 °C Td
S231: 4 mA = -50 °C Td;
20 mA = +20 °C Td
Update rate3 / sec
Update rate1/s
Voltage supply15 ... 30 VDC
Current consumption40 mA @ 24 VDC


PC SoftwareS4C-DP Application
Process connectionStainless steel 1.4301 (SUS 304)
HousingAluminium alloy
SensorPolymer, Ceramic
Electrical connectionScrew terminals
Protection classIP67
ApprovalsII 2G Ex db ib IIC T4 Gb
II 2D Ex ib tb IIIC T135°C Db
Process connectionG 1/2“ thread (ISO 228/1)
Weight728 g
Operating conditions
MediumAir, Argon, O₂, N₂, CO₂*
Medium qualityISO 8573-1: 4.6.3 or better
Medium temperature-30 ... +70 °C
Medium humidity≤ 20 °C Td
Operating pressure (model depending)-0.1 ... 1.6 MPa (S230)
-0.1 ... 35 MPa (S231)
Ambient temperature0 ... +50 °C
Ambient humidity0 ... 100 % rH
Storage temperature-20 ... +50 °C
Transport temperature-30 ... +70 ºC
Stated accuracy under following conditions:
Ambient temperature 23 °C ±3 °C
Process temperature 23 °C ±3 °C
Ambient humidity < 95 %, no condensation
Airflow > 2 l/min at sensor tip

S230 / S231

S230 / S231
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S230 / S231

Info sheets
S230 / S231
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S201/ S211/ S212/ S215/ S217/ S220/ S230/ S231/ S305/ S505/ S520 – CE & UKCA DECLARATION OF CONFORMITY

S201/ S211/ S212/ S215/ S217/ S220/ S230/ S231/ S305/ S505/ S520 – CE & UKCA DECLARATION OF CONFORMITY
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S4C-DP S2XX Service Software: V1.4

S4C-DP S2XX Service Software: V1.4
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