Temperature-Humidity Transmitter
Polwax RHT301 DM
Part Code. 0397
- Without Display
- Modbus RTU RS485
- Duct mounted
- Excellent linearity
- Wide sensing range
- Good long term stability
The Polwax RHT301 DM is a precision duct‑mounted temperature and humidity transmitter designed for demanding HVAC, industrial, pharmaceutical, and clean‑environment applications. It delivers accurate real‑time measurements of both temperature and relative humidity, with robust outputs and optional enhanced sensor variants to suit varied monitoring needs. Featuring streamlined installation, advanced communication options, and a rugged IP‑rated enclosure, the RHT301 DM ensures dependable environmental data for climate control and automation systems.
High‑temperature and high‑accuracy version offering enhanced measurement precision and extended range for demanding environments.
High‑temperature variant designed for extended temperature range applications while maintaining precise humidity sensing.
Product Overview
The Polwax RHT 301DM is a high-precision duct-mounted temperature and humidity transmitter, engineered for accurate environmental monitoring across demanding applications. Equipped with an integrated display, it provides real-time data visualization, enabling fast and informed decision-making. With a wide measurement range of -40°C to 85°C for temperature and 0–100% RH for relative humidity, it is ideal for industries such as HVAC, cleanrooms, food storage, and industrial automation.
Constructed with a robust 300 mm stainless steel sensor and filter, the RHT 301DM ensures long-term durability and reliable performance even in harsh environments. It delivers high-precision measurements with temperature accuracy of ±0.4°C and humidity accuracy of ±1.8%, meeting the stringent requirements of critical applications. Its IP54-rated enclosure provides protection against dust and moisture, ensuring consistent operation under challenging conditions.
The transmitter supports versatile output options, including 4–20 mA, RS485 MODBUS RTU, and an optional 0–10 V, allowing seamless integration with modern automation and control systems. User-friendly GUI software simplifies configuration, range selection, and device setup, enabling easy customization to specific application needs.
Designed for duct mounting, the RHT 301DM is essential for air handling and ventilation systems, combining advanced technology with practical features such as a real-time display to enhance operational efficiency and minimize downtime. The transmitter comes complete with a calibration certificate, GUI software, SS adaptor, and user manual, ensuring smooth installation and reliable operation.
Standard duct‑mounted temperature & humidity transmitter with a 300 mm SS sensor for reliable environmental monitoring in HVAC and industrial systems.
Standard model for accurate temperature and humidity measurement with versatile output options. High‑temperature and high‑accuracy version offering enhanced measurement precision and extended range for demanding environments.
Applications
Agriculture & Greenhouses
Ensure optimal plant growth and resource use with precise climate monitoring. The Polwax RHT301 DM delivers real‑time temperature and humidity data, helping manage greenhouse environments for healthier crops and improved yields
Pharmaceutical
Maintain strict environmental conditions required in pharmaceutical production and storage. The RHT301 DM’s high accuracy and stability support quality control, compliance, and product integrity in sensitive pharmaceutical spaces.
Storage & Warehouse
Protect valuable inventory by keeping temperature and humidity within safe limits. With reliable, continuous monitoring, the RHT301 DM helps prevent spoilage, condensation, and environmental damage in storage and warehouse facilities.
Food & Beverage
Support food safety and quality throughout processing and storage. Accurate humidity and temperature monitoring with the RHT301 DM ensures fresh, safe products and helps comply with regulatory standards in food and beverage environments.
HVAC
Enhance indoor climate control and energy efficiency in HVAC systems. By feeding precise environmental data into control systems, the RHT301 DM enables smarter ventilation, heating, and cooling for comfortable and efficient buildings.
Clean Rooms
Achieve strict environmental control in clean rooms and controlled spaces. The RHT301 DM provides dependable temperature and humidity monitoring critical for contamination‑free environments in labs, manufacturing, and research areas.
Technical Data
| Media Compatibility | Air, non-combustible, non-corrosive gases |
| Model No |
RHT301 DM / RHT301 DM / RHT301 DM (HT) / RHT301 DM (HT+HA) |
| Part Code |
0397 3151 / 0397 3152 / 0397 3153 / 0397 3154 |
| Measuring Range |
T: -40 to 85 °C & RH: 0–100% / T: 0 to 100 °C & RH: 0–100% / T: -40 to 125 °C & RH: 0–100% / T: -40 to 125 °C & RH: 0–100% |
| Accuracy |
T: ±0.4 °C & RH: ±1.8% / T: ±0.4 °C & RH: ±1.8% / T: ±0.4 °C & RH: ±1.8% / T: ±0.1 °C & RH: ±0.8% |
| Display | Without Display |
| Inputs | Temperature & Humidity |
| SS Probe Length | 301 mm |
| Dimensions | 75 × 35 × 75 mm |
| Protection Class | IP54 |
| Mounting | Duct Mount |
| Language | English |
| Supply Voltage | 24V DC |
| Output | 4–20mA, RS485 MODBUS RTU / 0–10V (Optional) |
| Scope of Supply | Calibration Certificate, GUI Software, SS Adaptor, Manual |
Temperature & Humidity Transmitter – RHT301 DM Series
The Polwax RHT301 DM series temperature and humidity transmitters are engineered for precise environmental monitoring in HVAC systems, clean rooms, pharmaceutical facilities, storage & warehouse areas, and industrial applications. With high accuracy and real-time data, these transmitters ensure optimal climate control and process efficiency.
Model Variants
RHT301 DM / RHT301 DM (HT) / RHT301 DM (HT+HA)
Duct Mount Design
Compact design allows duct mounting for flexible installation in any environment.
Accurate Monitoring
Precise measurement of temperature and humidity to maintain controlled environmental conditions.
Real-Time Display
Built-in display enables instant on-site readings for quick verification (for display variants).
Industrial Output Options
Supports 4–20 mA, RS485 MODBUS RTU, and 0–10 V (optional) outputs for seamless integration.
Wide Application Use
Suitable for HVAC, clean rooms, pharmaceutical facilities, storage & warehouse areas.
Reliable Protection
IP54 protection ensures stable operation in industrial and demanding environments.
24V DC Supply
Designed for continuous operation with standard 24V DC power supply.
