![Belimo 22DT-54R : Duct/Immersion Temperature Sensor, Active 4-20mA Output, 8 Measuring Ranges, Probe length 12" [300 mm], IP65, NEMA 4X Enclosure, 5-Year Warranty](https://cdn11.bigcommerce.com/s-ksbdsp5vfo/images/stencil/1280x1280/products/5961/49060/BelimoTemperature-1-DuctTemperature__04516.1719971859.png?c=1 "Belimo 22DT-54R : Duct/Immersion Temperature Sensor, Active 4-20mA Output, 8 Measuring Ranges, Probe length 12\" [300 mm], IP65, NEMA 4X Enclosure, 5-Year Warranty")
![Dimensional Drawing for Belimo 22DT-54R : Duct/Immersion Temperature Sensor, Active 4-20mA Output, 8 Measuring Ranges, Probe length 12" [300 mm], IP65, NEMA 4X Enclosure, 5-Year Warranty](https://cdn11.bigcommerce.com/s-ksbdsp5vfo/images/stencil/1280x1280/products/5961/49061/BelimoTemperature-2-DuctTemperatureDimensions__46446.1719971859.png?c=1 "Dimensional Drawing for Belimo 22DT-54R : Duct/Immersion Temperature Sensor, Active 4-20mA Output, 8 Measuring Ranges, Probe length 12\" [300 mm], IP65, NEMA 4X Enclosure, 5-Year Warranty")
![Belimo 22DT-54R : Duct/Immersion Temperature Sensor, Active 4-20mA Output, 8 Measuring Ranges, Probe length 12" [300 mm], IP65, NEMA 4X Enclosure, 5-Year Warranty](https://cdn11.bigcommerce.com/s-ksbdsp5vfo/images/stencil/500x659/products/5961/49060/BelimoTemperature-1-DuctTemperature__04516.1719971859.png?c=1 "Belimo 22DT-54R : Duct/Immersion Temperature Sensor, Active 4-20mA Output, 8 Measuring Ranges, Probe length 12\" [300 mm], IP65, NEMA 4X Enclosure, 5-Year Warranty")
The 22DT-54R is a Belimo active 24V duct temperature transmitter with a 12" (300 mm) stainless steel insertion probe, a Pt 1000 sensing element, and 4–20 mA (loop-powered) output. The transmitter ships with eight jumper-selectable measuring ranges (S0–S7) — pick the range that best matches your supply, return, or mixed-air monitoring window for highest output resolution. The orange UV-resistant polycarbonate housing mounts to the duct exterior; the probe penetrates through a single hole.
Supply, return, mixed-air, and outdoor-air duct temperature in air handlers and rooftop units. The 12" probe is appropriate for medium-to-large commercial ducts. Choose the active 22DT over the passive 01DT when your BAS controller does not have a Pt 1000 input curve, when long cable runs would introduce resistance error on a passive sensor, or when you want jumper-selectable range narrowing for higher analog resolution.
Key Features
Onboard jumper selects one of eight measuring ranges (S0–S7), letting you narrow the output span to your actual monitoring window for higher analog resolution. Factory default is S0 (-30 to 130°F).
Two-wire 4–20 mA current loop output, max loop resistance 500 Ω. Preferred for long cable runs — current-mode signaling is immune to voltage-drop errors that affect 0-10V signals over distance.
12" (300 mm) stainless steel insertion probe penetrates the duct through a single mounting hole. Probe is sealed for moisture and rated for continuous duct service.
21.6–26.4 VAC or 13.5–26.4 VDC; 0.8 VA / 0.4 W. Pluggable spring-loaded terminal block for fast wiring.
Pt 1000 class AA platinum RTD delivers ±0.9°F accuracy at 70°F. Long-term stability ±0.07°F per year — no field calibration required.
Industry-leading factory warranty backed by Belimo's worldwide service network.
Selectable Measuring Ranges (S0–S7)
Eight ranges are available via onboard jumper. Select the range whose span best matches your monitoring window — narrower ranges deliver higher analog resolution. The factory default is S0 (-30 to 130°F).
| Setting | Range (°F) | Range (°C) | Note |
|---|---|---|---|
| S0 | -30 to 130°F | -50 to 50°C | Factory default |
| S1 | 0 to 250°F | -10 to 120°C | |
| S2 | 40 to 140°F | 0 to 50°C | |
| S3 | 30 to 480°F | 0 to 250°C | |
| S4 | 0 to 100°F | -15 to 35°C | |
| S5 | 40 to 240°F | 0 to 100°C | |
| S6 | 40 to 90°F | -20 to 80°C | |
| S7 | 0 to 150°F | 0 to 160°C |
Technical Specifications
| Specification | Detail |
|---|---|
| Sensor Style | Active duct insertion temperature transmitter — 12" probe |
| Measured Value | Temperature |
| Sensing Element | Pt 1000 class AA platinum RTD |
| Output Signal | 4–20 mA (loop-powered) — max. 500 Ω loop resistance |
| Multirange | 8 jumper-selectable measuring ranges (S0–S7); see table above |
| Default Range | -30 to 130°F (S0) (factory setting) |
| Default Temperature Units | Fahrenheit (°F) |
| Regional Variant | North American |
| Accuracy | ±0.9°F (±0.5°C) at 70°F (21°C), measured on S2 / S4 ranges |
| Long-Term Stability | ±0.07°F per year (±0.04°C per year) |
| Time Constant τ (63%) | Typical 30 s @ 6 m/s air velocity |
| Probe Length | 12" [300 mm] |
| Probe Diameter | 0.24" [6 mm] |
| Probe Material | Stainless steel |
| Application | Air — duct insertion |
| Mounting | Single-hole duct penetration; A-22D-A11 mounting clip included |
| Conduit | 1/2" NPT conduit adapter included |
| Power Supply | 24 VAC/VDC (21.6–26.4 VAC, 13.5–26.4 VDC) |
| Power Consumption | 0.8 VA AC / 0.4 W DC |
| Electrical Connection | Pluggable spring-loaded terminal block, max 2.5 mm² |
| Cable Entry | Cable gland with strain relief, ø6...8 mm |
| Housing | UV-resistant polycarbonate, orange — UL94 5VA |
| Enclosure Rating | NEMA 4X / IP65 (UL Enclosure Type 4X), UL 2043 plenum compliant |
| Protection Class | IEC/EN III, PELV; UL Class 2 supply |
| UL Approval | cULus per UL60730-1A/-2-9, CAN/CSA E60730-1/-2-9 |
| Manufacturer | Belimo |
| Manufacturer Part Number | 22DT-54R |
| Warranty | 5-year factory warranty |
What's In the Box
- 22DT-54R active duct temperature transmitter with 12" (300 mm) stainless probe
- A-22D-A11 mounting clip (with screws and adhesive foil)
- 1/2" NPT conduit adapter
Documentation
Frequently Asked Questions
What output signal does the 22DT-54R provide?
4–20 mA (loop-powered), with max. 500 Ω loop resistance. Two-wire 4-20mA current loop — preferred for long cable runs because the loop is immune to voltage-drop errors that affect 0-10V signals over distance.
How do the 8 selectable measuring ranges work?
An onboard jumper selects one of 8 ranges, S0 through S7, each spanning a different temperature window. Factory default is S0 (-30 to 130°F), the widest range. Once you know your actual monitoring window, switching to a narrower range gives higher analog resolution because the same output span maps to a smaller temperature range.
Does this need 24V power?
Yes. The 22DT-54R is an ACTIVE transmitter — it requires 24 VAC or 24 VDC (21.6-26.4 VAC or 13.5-26.4 VDC). Power consumption is 0.8 VA AC / 0.4 W DC.
What probe length is on the 22DT-54R?
This SKU has a 12" (300 mm) probe. The 22DT family ships in six probe lengths: H=2", L=4", N=6", P=8", R=12", T=18". Select the length that penetrates roughly to the centerline of your duct for best representative reading.
How is this different from the passive 01DT?
The 01DT family is a passive resistance temperature sensor — it sends raw Pt 1000 (or NTC, Ni 1000) resistance to your controller. The 22DT is an active 24V transmitter — it applies onboard signal conditioning and outputs a scaled 0-10V or 4-20mA signal. Choose passive when your BAS has Pt 1000/NTC inputs and you want fewer parts and no power supply. Choose active when your BAS only accepts voltage/current inputs, when you need long cable runs, or when you want jumper-selectable range narrowing for higher resolution.
Does it work with my BAS?
Any BAS controller with a 4–20 mA analog input will read this transmitter directly. Set the controller input scale to match the selected measuring range — no special curve or driver needed.
- Sensor Type:
- Probe Only
- Output Signal:
- Temperature Only
- Output Style:
- Active Transmitter (4-20mA)
- Power:
- 24 VAC/VDC
- Temperature Element:
- Active Transmitter (4-20mA)
- Sensing Element:
- Pt 1000 class AA
- Multirange:
- 8 Selectable Ranges (S0-S7)
- Default Range:
- -30 to 130°F (S0)
- Default Temperature Units:
- Fahrenheit (°F)
- Regional Configuration:
- North American (°F + NPT)
- Probe Length:
- 12 Inch
- Humidity Element:
- None
- CO2 Element:
- None
- VOC Element:
- None
- Display:
- No Display
- Setpoint:
- No Setpoint
- Override:
- No Override
- Supported Protocols:
- None (analog)
- Enclosure:
- NEMA 4X Enclosure
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