The Belimo EXT-RT-SS10K2 is a stainless steel wall-plate room temperature sensor built for spaces that demand a vandal- and tamper-resistant form factor. A precision 10K Type II Thermistor (NTC10k2) element is embedded behind a single-gang stainless plate with no dials, buttons, or screws to defeat. Insulating foam on the back of the plate decouples the sensor from in-wall thermal mass for accurate room-air readings, and the 2-wire output connects directly to any DDC controller that accepts this resistance curve.
Key Features
Tamper-Resistant Stainless Plate
Single-gang stainless wall plate with no exposed dials, buttons, or fasteners. Ideal for K-12, dorms, lobbies, and corridor installations where occupants might tamper with traditional plastic sensors.
10K Type II Thermistor (NTC10k2) Element
10,000 Ohm Type II NTC thermistor, ±0.2°C. Accuracy ±0.2°C @ 25°C [±0.36°F @ 77°F]. Wire directly to any DDC controller that accepts this resistance curve — no power supply required.
Insulating Foam Thermal Barrier
Foam adhered to the back of the wall plate decouples the sensor from in-wall thermal mass and air movement, giving a more accurate reading of true room air temperature.
Single-Gang Flush Mount
Mounts directly to a standard single-gang electrical box or flat to drywall. 2-wire termination simplifies retrofits — drop into the same box that held the previous wall sensor.
Technical Specifications
| Specification | |
|---|---|
| Sensor Element | 10,000 Ohm Type II NTC thermistor, ±0.2°C |
| Output Signal | Passive (2-wire resistance) |
| Accuracy | ±0.2°C @ 25°C [±0.36°F @ 77°F] |
| Ambient Operating Range | -4...140°F [-20...60°C] |
| Enclosure | Stainless Steel |
| Protection | IP50 / NEMA 1 |
| Dimensions | 4.5 x 2.75 x 0.1875 in [114.3 x 69.85 x 4.75 mm] |
| Termination | 2-wire |
| Mounting | Single-gang electrical box or flat-wall flush mount |
| Quality Standard | ISO 9001 |
| Country of Origin | Canada |
Documentation
Frequently Asked Questions
Why choose a stainless wall plate over a plastic room sensor?
The EXT-RT-SS10K2 eliminates the dial, button, and visible fasteners that tend to fail or get tampered with in schools, dormitories, and public corridors. The stainless plate is durable, easy to clean, and replaceable from the front of the box.
Does this sensor have a setpoint or manual override?
No. The EXT-RT-SS series is intentionally minimal — temperature sensing only, no occupant-accessible controls. If you need a setpoint dial in a tamper-resistant form, use a wall sensor with locked covers; if you need an occupant override, route a separate wall-mounted button.
How accurate is the reading?
Accuracy is ±0.2°C @ 25°C [±0.36°F @ 77°F]. The insulating foam on the back of the plate decouples the sensor from in-wall thermal mass, yielding a true room-air reading rather than a wall-temperature reading.
What's the operating range outside the room?
The EXT-RT-SS10K2 is rated -4...140°F [-20...60°C] ambient, wider than the typical 0-50°C indoor sensor. It will also work in unconditioned mechanical rooms, light vestibules, and similar environments.
How does it install into an existing single-gang box?
The plate mounts to the box with two screws (included). Spring-loaded terminals or wire nuts can be used to land the 2-wire passive output on the controller. The plate dimensions match a standard single-gang configuration.
- Sensor Type:
- Wall Plate
- Temperature Element:
- 10K Type II
- Supported Protocols:
- None
- Humidity Element:
- None
- CO2 Element:
- None
- Setpoint:
- Setpoint
- Override:
- No Override
- Display:
- No Display
- Material:
- Stainless Steel
