The Belimo 01UT-5M is a passive outdoor air temperature sensor with a NTC 10K Type III (10k3, Precon) thermistor sensing element in a UV-resistant polycarbonate NEMA 4X / IP65 enclosure, rated for a measuring range of -30...122°F [-35...50°C]. It mounts to an exterior wall on the included A-22D-A09 mounting plate and lands in 1/2″ NPT conduit through the included adapter. The element is read directly by the building controller as a resistance, so no 24 V supply and no signal conditioning are required.
Specifications on this page are taken from the Belimo 01UT-5.. technical data sheet (document footer dated 2023-11-21) and the Belimo resistance characteristics document (footer dated 2023-10), as held in the ZOT Supply controlled document library. Verified 2026-08-26.
Outdoor air temperature sensing on exterior building walls and weather-exposed mechanical platforms. Belimo lists cold stores, greenhouses, production plants and warehouses as the typical applications for this sensor. Specify the NTC 10K (10k3) version when the controller input is already configured for that curve.
Key Features
Weather-Rated Enclosure
Polycarbonate housing with an NBR70 seal, rated NEMA 4X / IP65 and UL Enclosure Type 4X. The housing material is listed UV resistant and UL94 5VA.
Mounting Kit Included
Ships with the A-22D-A09 S-housing mounting plate, dowels, screws and a 1/2″ NPT conduit adapter. No separate hardware pull is needed for a standard wall install.
NTC 10K Type III Element
Published accuracy of ±0.35°F @ 77°F [±0.2°C @ 25°C]. Measuring current <2.7 mA @ 77°F [25°C].
No Supply Voltage Needed
The passive resistance element returns directly to a compatible controller temperature or resistance input. No 24 V supply, no transmitter, no scaling.
Pluggable Terminal Block
Spring-loaded pluggable terminal block accepts conductors up to 2.5 mm². The block lifts out for bench wiring and snaps back in.
Plenum Rated
UL 2043 compliant and suitable for use in air plenums per NEC Section 300.22(C) and IMC Section 602.
Technical Specifications
| Specification | Detail |
|---|---|
| Sensor Style | Outdoor air temperature sensor, wall mount, element internal to housing |
| Measured Value | Temperature |
| Application | Air |
| Sensing Element | NTC 10K Type III (10k3, Precon) thermistor |
| Output Signal | Passive temperature (resistance) |
| Measuring Range | -30...122°F [-35...50°C] |
| Accuracy | ±0.35°F @ 77°F [±0.2°C @ 25°C] |
| Measuring Current | <2.7 mA @ 77°F [25°C] |
| Time Constant τ (63%) | Typical 854 s in the room |
| Ambient Temperature | -35...50°C [-30...122°F] |
| Fluid Temperature | -35...50°C [-30...122°F] |
| Ambient Humidity | Max. 95% RH, non-condensing |
| Housing Surface Temperature | max. 195°F [90°C] |
| Electrical Connection | Pluggable spring-loaded terminal block, max. 2.5 mm² |
| Cable Entry | Cable gland with strain relief ø6...8 mm; 1/2″ NPT conduit adapter included |
| Housing | Cover and bottom polycarbonate; seal NBR70; UV resistant; UL94 5VA |
| Cable Gland | PA6 |
| Mounting Plate | Polycarbonate, grey RAL 7001 |
| Enclosure Rating | NEMA 4X / IP65 (UL Enclosure Type 4X) |
| Protection Class | IEC/EN III, Protective Extra-Low Voltage (PELV) |
| Power Source | UL Class 2 Supply |
| Agency Listing | cULus Listed — UL category 94D5, Temperature Indicating & Regulating Equipment |
| Certification IEC/EN | IEC/EN 60730-1 |
| EU Conformity | CE Marking |
| Quality Standard | ISO 9001 |
| Plenum Compliance | Suitable for use in air plenums per Section 300.22(C) of the NEC and Section 602 of the IMC (UL 2043 compliant) |
| Type of Action | Type 1 |
| Rated Impulse Voltage | 0.8 kV |
| Pollution Degree | 3 |
| Parts Included | Mounting plate, S housing — type A-22D-A09; Dowels; Screws; 1/2″ NPT conduit adapter |
| Weight | 0.26 lb [0.12 kg] |
| Manufacturer | Belimo |
| Manufacturer Part Number | 01UT-5M |
| Warranty | 5 years |
Documentation
Belimo 01UT-5.. Technical Data Sheet- 01UT / 22UT Installation Instructions
- Resistance Characteristics — Passive Temperature Sensors
- Belimo Sensors Brochure
Related Products
- Belimo 01UT-5A — Pt 100 outdoor air temperature sensor
- Belimo 01UT-5B — Pt 1000 outdoor air temperature sensor
- Belimo 01UT-5E — Ni 1000 outdoor air temperature sensor
- Belimo 01UT-5L — NTC 10K (10k2) outdoor air temperature sensor
- Belimo 01UT-5Q — NTC 20K outdoor air temperature sensor
- Belimo 22UT-52 — active outdoor air sensor, 0-5 V / 0-10 V output
- Belimo 22UT-54 — active outdoor air sensor, 4-20 mA output
Frequently Asked Questions
Does the Belimo 01UT-5M require 24 V power?
No. The 01UT-5M is a passive resistance temperature sensor. The controller reads the resistance element directly through a compatible temperature or resistance input, so the sensor itself needs no supply voltage, transmitter or signal conditioner. The controller input must be configured for the NTC 10K (10k3) curve.
What sensing element does the Belimo 01UT-5M use?
The 01UT-5M uses a NTC 10K Type III (10k3, Precon) thermistor. The suffix letter identifies the element across the family: A = Pt 100, B = Pt 1000, E = Ni 1000 (JCI), L = NTC 10K Type II, M = NTC 10K Type III (Precon), Q = NTC 20K.
What is the measuring range of the Belimo 01UT-5 series?
Belimo publishes a measuring range of -30...122°F [-35...50°C]. Note that Belimo prints the Fahrenheit and Celsius figures as regional standard ranges rather than as conversions of each other.
What is the accuracy of the Belimo 01UT-5M?
Belimo publishes ±0.35°F @ 77°F [±0.2°C @ 25°C] for this element.
What is the response time of the Belimo 01UT-5 series?
The published time constant τ (63%) is typically 854 s in the room, roughly 14 minutes to reach 63% of a step change. A long time constant is normal for a weatherproof outdoor enclosure, where a damped average is more useful than a fast response to transient gusts.
Does cable length affect the reading on a passive sensor?
It can. Belimo notes that with two-wire passive sensors the supply current causes self-heating, so the controller current should not exceed the measuring current listed for the element (<2.7 mA @ 77°F [25°C] for this model). Belimo also notes that on long runs the cable resistance must be accounted for, and that the lower the sensor impedance the larger the offset the line resistance produces.
What is included with the Belimo 01UT-5M?
Belimo lists the following parts included: mounting plate, s housing — type a-22d-a09; dowels; screws; 1/2″ npt conduit adapter.
Is the Belimo 01UT-5 series listed for plenum use?
Yes. Belimo lists the product as UL 2043 compliant and suitable for use in air plenums per NEC Section 300.22(C) and IMC Section 602.
- Sensor Type:
- Outdoor Air
- Output Signal:
- Temperature Only
- Temperature Element:
- 10K Type III
- Humidity Element:
- None
- CO2 Element:
- None
- VOC Element:
- None
- Display:
- No Display
- Setpoint:
- No Setpoint
- Override:
- No Override
- Supported Protocols:
- None
- Enclosure:
- NEMA 4X Enclosure
