Relative humidity sensor 3S-RH-I

capacitive4-20 mAcurrent output

Product description
The 3S-RH-I is a capacitive relative humidity sensor providing an analog 4–20 mA output for direct integration with dataloggers, gateways and PLCs. It measures relative humidity from 0 to 100 % RH and is supplied with mounting accessories and a UV‑resistant radiation shield to protect the sensing element from direct sunlight.

Working principle
A capacitive sensing element on an electronic board measures ambient relative humidity with high sensitivity. The sensor electronics convert the measurement to an analog 4–20 mA signal. The sensor is housed in a UV‑resistant enclosure with a protective shield designed for outdoor and demanding climatic conditions.

Applications

• Solar energy systems and PV performance monitoring
• Industrial process control
• Production facilities
• Storage areas and warehouses
• Environmental monitoring in transport vehicles
• Humidity control for protection of moisture‑sensitive products and equipment

Installation guidance
Test the system at ground level before final installation. Install the sensor away from dark, reflective or heat‑absorbing surfaces and avoid proximity to heat sources (chimneys, vents). On rooftops, mount the sensor on the side exposed to the prevailing wind. Installation is performed in two stages: install the mounting structure first, then attach the sensor to the mounting frame.

Why choose Seven Relative Humidity Sensor

• High accuracy: ±1 % RH (20–70 %) at 25 °C with 0.1 % resolution for reliable measurements.
• Weather resistance: UV‑resistant shield and ABS enclosure for robust outdoor operation.
• Easy integration: Standard analog 4–20 mA output compatible with dataloggers, gateways and PLCs.

Additional product information

• Warranty: 2 years for model 3S-RH-I.
• Price indication: typically between 250 and 300 EUR.
• Delivery times: small orders (up to 5 pcs): approx. 2–3 weeks; bulk orders (up to 100 pcs): approx. 7–9 weeks.
• Cable: each unit supplied with a 3 m LIYYC11Y PUR cable (UV and weather resistant); other lengths available on request.

Technical specifications

• Item code: 3S-RH-I
• Measured data: Relative Humidity
• Sensor type: Capacitive
• RH range: 0 % to 100 %
• RH accuracy: ±1 % RH (20–70 %) at 25 °C
• RH resolution: 0.1 %
• Data output: Analog 4–20 mA
• Power supply: 12 to 30 V DC
• Power consumption: 30 mA @ 24 V DC
• Electrical connection: 3 m LIYYC11Y PUR cable (UV and weather resistant)
• Operating temperature range: -40 °C to +85 °C
• Box dimensions: 64 x 68 x 35 mm (W x L x H)
• Shield dimensions: Ø 105 x 100 mm
• Weight: 0.5 kg
• IP rating: IP65
• Box material: ABS
• Sensor housing material: Stainless steel tube – membrane filter
• Shield material: ABS
• Standard: Class A according to IEC 61724-1:2021 (Relative Humidity)