USB Infrared Temperature Sensor for Benchtop, Laboratory and Education

    Sensor Features

  • Miniature non-contact temperature sensor with USB communications
  • Measures temperatures from -20°C to 1000°C
  • USB cable included
  • Free software for data logging and configuration
  • Modbus protocol - use your own software to communicate with the sensor

    Software (CalexConfig and CalexSoft 2)

  • Temperature display, graph, configuration and data logging
  • Connect multiple sensors to the same software (CalexSoft 2)
  • Free download from Calex

The PyroMiniUSB is a miniature USB pyrometer. It is ideal for use in benchtop, laboratory and education applications.

General Specifications

Temperature Range
-20°C to 1000°C
±1% of reading or ±1ºC whichever is greater
± 0.5% of reading or ± 0.5°C whichever is greater
0.2 to 1.0
Response Time, t90
125 ms (90% response)
Spectral Range
8 to 14 μm
Supply Voltage
5 V DC
Supply Current
50 mA max.
Baud Rate
9600 baud (other configurations available upon request)
Modbus Data Format
8 data bits, no parity, 1 stop bit (other configurations available upon request)
Modbus over Serial Line


Configuration Method
Via USB using CalexConfig, CalexSoft 2, or other Modbus software (see Operator's Guide for Modbus details)
Configurable Parameters
Emissivity Setting, Averaging, Reflected Energy Compensation

Field of View Diagrams

Please note: The given measured spot size contains 90% of the energy detected by the sensor. We normally recommend the target is at least twice as large as the given measured spot for maximum accuracy. Sensors may be used at longer distances than the above diagrams show. There is no maximum measurement distance in clean air; this is because Calex sensors detect only the wavelengths of infrared radiation that are not absorbed by the atmosphere.

Mechanical Specifications

Stainless Steel
18 mm diameter x 45 mm long (excluding cable gland)
Thread Mounting
M16 x 1 mm pitch
USB Cable Length
1.5 m
Weight with Cable
85 g

Environmental Specifications

Environmental Rating IP65
Ambient Temperature Range 0°C to 75°C
Relative Humidity 95% max. non-condensing

Electromagnetic Compatibility Standards

EN61326-1, EN61326-2-3 (Electrical Equipment for Measurement, Control and Laboratory Use – EMC Requirements – Industrial)

Typical Applications

Benchtop and Laboratory
With the precision and robustness of our industrial pyrometers, and the plug-and-play convenience of USB, the PyroMiniUSB is the ideal benchtop temperature sensor for testing and experimentation.
The PyroMiniUSB is ideal for teaching science concepts such as emissivity, reflectivity, thermal conductivity, energy transfer, insulation and internal energy.
Calibration Checking
Combined with a blackbody calibration source, the PyroMiniUSB makes the ideal calibration reference pyrometer. Keep one in your calibration room and check the performance of your other sensors against it. Calex can provide calibration certificates for traceability.

Electrical Installation

Just plug the sensor directly into the USB port of a PC or laptop.

The sensor is USB powered – no other power supply is required.

Software Installation

The PyroMiniUSB is compatible with the free Calex software, CalexConfig and CalexSoft 2.

Download the software here

Alternatively you can communicate with the sensor from third-party software using the Modbus protocol. For details of the Modbus registers, see the PyroMiniUSB Instruction Manual.

Dimensions (mm)

Air Purge Collar

The air purge collar is used to keep dust, fumes, moisture and other contaminants away from the lens. Air flows into the fitting on the side and out of the aperture at the front.

Fixed Mounting Bracket

This stainless steel bracket provides a rigid support for the sensor and rotational adjustment in 1 axis.

Adjustable Mounting Bracket

This stainless steel mounting bracket provides rotational adjustment about 2 axes.

Two models are available:

PMU21     PyroMiniUSB sensor with 2:1 optics – for large or close-up targets

PMU201   PyroMiniUSB sensor with 20:1 optics – for small or more distant targets

To find out how to order in your region, contact us