The BTU-4D Burk Digital Temperature Unit connects up to four digital temperature sensors to an ARC Solo remote control or to a Plus-X input device in an ARC Plus system. Sensor cables up to 1000 feet long are supported without measurement degradation. The unit also provides a low voltage output sample that tracks linearly with the AC line voltage.

Each temperature output supplies 10mV per degree Fahrenheit or Celsius, based on a jumper setting on the BTU-4D/BTU-4D-I.

The BTU-4D/BTU-4D-I  is supplied with:

  • One 120 V AC power adapter for BTU-4D or a 220V AC power adapter for BTU-4D-I  
  • One TEMP-OUTDOOR sensor for either Fahrenheit or Celsius temperature measurement 
  • One 6‐terminal Phoenix-style plug for connection to monitoring equipment 


0.95” (2.41 cm) H
3.01” (7.65 cm) D
3.11” (7.91 cm) W excluding mounting flangess
4.05” (10.28 cm) W including mounting flanges


12VAC wall adapter (provided)


4  RJ-12 jacks for connection of digital temperature sensors
6-terminal plug providing four temperature samples and one AC line sample

Temperature Range:

BTU-4D: 0C to 40C
Sensors: -55C to 125C, ± 0.5C from –10C to 85C
10mV per degree Fahrenheit or Celsius, based on jumper setting

AC Voltage Sample:

BTU-4D:  22.6 mV per AC volt ± 3%, 100VAC to 140VAC
BTU-4D-I:  11.3 mV per AC volt ± 3%, 200VAC to 240VAC


TEMP-INDOOR: Requires Burk SENSOR CABLE, not included
TEMP-WALLMOUNT: Includes 14’ prewired cable
TEMP-OUTDOOR: Includes 25’ prewired cable
TEMP-STACK: includes 25’ prewired cable



The TEMP-INDOOR Sensor is a general-purpose, digital, indoor temperature sensor tailored for monitoring ambient temperatures within a room or in an equipment rack. Temperature accuracy: ±0.5° C from -10° C to 85° C. Cables are not supplied with this sensor — order 25’ RJ-12 cable, part number SENSOR CABLE.



The TEMP-WALLMOUNT Sensor is housed in a 2 5/8” x 5” enclosure with air vents to facilitate sensing of the environment. Temperature accuracy: ±0.5° C from -10° C to 85° C. A 14’ cable is provided with an RJ-12 connector on one end. The TEMP-INDOOR has a large, easy to connect barrier strip that accommodates flat or Phillips type screwdrivers



The TEMP-OUTDOOR digital outdoor temperature sensor is included with the BTU‐4D/BTU-4D-I systems, and is intended for general purpose monitoring of equipment or ambient temperatures. Temperature accuracy: ±0.5° C from -10° C to 85° C. The TEMP-OUTDOOR sensor is attached to 25’ of cable with an RJ-12 connector on the end. The sensor has a mounting ring and gasket to accommodate #6 or #8 hardware. The sensing elements are sealed for added protection from dirt and moisture.



The TEMP-STACK Sensor is a digital stack temperature sensor designed for sensing heat within the air ducting of your equipment. Temperature accuracy: ±0.5° C from -10° C to 85° C. The TEMP-STACK Sensor is attached to 25’ of cable with an RJ-12 connector. The sensor is mounted in the tip of a 3/8” diameter chrome tube. The supplied mounting hardware consists of a base and a compression fitting to allow the sensor to be secured at variable depths. This allows the installer to locate the sensor up to 9 1/2” from the equipment wall, well within the airflow being monitored.

Ordering information

Part #Product
BTU-4DBTU-4D 120VRequest quote

Digital Temperature Unit, 120V, selectable Fahrenheit or Celsius

BTU-4D-IBTU-4D-I 240VRequest quote

Digital Temperature Unit, 240V, selectable Fahrenheit or Celsius

TEMP-INDOORDigital Indoor Temperature SensorRequest quote

Digital indoor temperature sensor for use with BTU-4D, BTU-4DI, Climate Guard and Plus-X EM

TEMP-WALLMOUNTDigital Wallmount Temperature SensorRequest quote

Digital wallmount temperature sensor for use with BTU-4D, BTU-4DI, Climate Guard and Plus-X EM

TEMP-OUTDOORDigital Outdoor Temperature SensorRequest quote

Digital outdoor temperature sensor for use with BTU-4D, BTU-4DI, Climate Guard and Plus-X EM

TEMP-STACKDigital Stack Temperature SensorRequest quote

Digital stack temperature sensor for BTU-4D, BTU-4DI, Climate Guard and Plus-X EM

Key Features

  • Connect up to 4 digital temperature sensors
  • Sensor cable length to 1000' without degradation
  • Selectable Fahrenheit or Celsius
  • One TEMP-OUTDOOR sensor included with each BTU-4D or BTU-4DI

User Documentation(View all)