Miniature Infrared Temperature Sensor with Separate Electronics Module


  • General-purpose models measure temperatures from -20°C to 1000°C
  • Short-wavelength models for improved accuracy on iron, steel, and high-temperature targets from 100°C to 2000°C
  • 4-20 mA or RS485 Modbus outputs
  • Miniature sensing head and configurable electronics module
  • Touch screen interface (optional)
  • High ambient temperature sensing head option for use in 180°C ambient temperature without cooling
  • Data logging to MicroSD Card (optional)
  • Not designed or approved for fever detection

General Specifications

Temperature Range
General purpose models: -20°C to 1000°C
Short-wavelength models: 100°C to 2000°C
Temperature range varies by model (see "Ordering")
4-20 mA or RS485 Modbus (Up to 247 sensors may be installed on a single Modbus network)
Field of View
Choice of wide-angle or focussed optics (see Field of View Diagrams below)
General purpose models: ± 1°C or 1% of reading, whichever is greater
Short-wavelength models: ± 2°C or 1% of reading, whichever is greater
± 0.5°C or 0.5% of reading, whichever is greater
Emissivity Setting
General purpose models: Adjustable, 0.20 to 1.00
Short-wavelength models: Adjustable, 0.10 to 1.00
Emissivity Setting Method
-CB models: via two rotary switches in electronics module
-BB and -BRT models: via RS485 Modbus
-CRT and -BRT models: via touch screen
Response Time, t90
240 ms (90% response)
Spectral Range
General purpose models: 8 to 14 μm
Short-wavelength models: 2.0 to 2.6 µm
Supply Voltage
24 V DC ± 5%
Maximum Current Draw
100 mA
Max. Loop Impedance (-CB and -CRT models)
900 Ω (4-20 mA output)
Alarm Relays (-CRT and -BRT models)
2 x Single Pole Changeover alarm relays, rated 24 V DC, 1 A, isolated 500 V DC

Data Logging Specifications

Data Logging Interval
1 to 86,400 seconds (1 day)
MicroSD Card
Max. capacity: 32 GB (not included, available separately)
Internal Clock Battery
1 x BR 1225 3V (not included)
Variables Logged
Target temperature, sensing head temperature, electronics module temperature, max, min, average, emissivity setting, reflected energy compensation temperature, alarm events
File format
Configurable Parameters
Sample period, number of samples, scheduled start date and time

Touch Screen Interface Specifications

Touch Screen Display Format
2.83” (72 mm) resistive touch TFT, 320 x 240 pixels, backlit
Configurable Parameters
Temperature range, temperature units, emissivity setting, reflected energy compensation, alarms, signal processing, Modbus address (-BRT models), date and time, data logging
Temperature Units
°C or °F configurable
Temperature Resolution
Alarm Configuration
Two alarms with adjustable level, individually configurable as HI or LO. Alarm 2 can be set to target temperature or sensing head internal temperature
Signal Processing
Average, peak hold, valley hold, minimum, maximum

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, and accuracy does not change with distance; this is because the PyroMini detects only the wavelengths of infrared radiation that are not absorbed by the atmosphere.

Mechanical Specifications

Construction (Sensing Head)
Stainless Steel 316
Construction (Electronics Module)
Die Cast Aluminium
Major Dimensions (Sensing Head)
18(dia.) x 45(l) mm (see diagram on data sheet)
Major Dimensions (Electronics Module)
98(w) x 64(h) x 36(d) mm
Mounting (Sensing Head)
M16 x 1 mm thread
Mounting (Electronics Module)
Requires two M4 screws for wall mounting (see diagram on data sheet)
Cable Length (sensing head to electronics module)
1 m (standard), up to 30 m (optional)
Weight with 1 m cable
390 g (approx)
Cable Connections
Removable screw terminal blocks (see "Connections" on data sheet)
Conductor size: 28 AWG to 18 AWG
Output Cable Gland
Suitable for cable diameters 3.0 to 6.5 mm

Electromagnetic Compatibility Standards

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

Environmental Specifications

Environmental Rating
Ambient Temperature Range
Relative Humidity
CE Marked
RoHS Compliant
Sensing Head
Environmental RatingIP65 (NEMA 4)
Ambient Temperature RangeGeneral Purpose models: Ranges from 0°C to 180°C, depending on model (see "Ordering"). Short Wavelength models: 0°C to 70°C
Relative HumidityMaximum 95% non-condensing
CE MarkedYes
RoHS CompliantYes
Electronics Module (without touch screen)
Environmental RatingIP65 (NEMA 4)
Ambient Temperature Range0°C to 60°C
Relative HumidityMaximum 95% non-condensing
CE MarkedYes
RoHS CompliantYes
Electronics Module (with touch screen)
Environmental Rating-
Ambient Temperature Range0°C to 60°C
Relative HumidityMaximum 95% non-condensing
CE MarkedYes
RoHS CompliantYes

The unique features of the PyroMini make it ideal for applications in a wide range of industries. For example, some typical uses include:

Typical Applications

Peak or valley hold processing makes the PyroMini ideal for measuring food temperature in vats, where stirring machinery interrupts the sensor's view of the food surface, and for measuring the temperature of food products on conveyors to ignore readings of the conveyor temperature. Data logging to MicroSD Card means the PyroMini may be used to satisfy HACCP requirements.

Hot stainless steel surfaces above 100°C can be measured quickly and accurately with the PyroMini 2.2. Applications include burner control in conveyor ovens and dryers.
Models with high-temperature sensing head (up to 180°C ambient) may be used in hot environments in corrugated board manufacturing and paper drying.

Dryer cylinder surface temperatures exceeding 100°C (such as in linerboard manufacturing) may be measured directly with the PyroMini 2.2. See also the PyroUSB 2.2 for temperatures below 100°C (in the manufacture of finer paper types).
In thermoforming, the 180°C sensing head is ideal for measuring the plastic sheet preheat temperature where the ambient temperature is high, without the need for cooling
Paint and Adhesive Curing
The high-temperature sensing head may be placed inside curing ovens up to 180°C without cooling. It is also ideal for use with infrared curing heaters.
Steel industry
Short-wavelength 2.2 μm sensors are better-suited to measuring steel surface temperature than general-purpose 8 to 14 μm models. Contact Calex for advice on measurement locations on annealing lines, furnaces, rolling mills and railway rail manufacturing.

Electrical Installation

Dimensions (mm)

PM180 6-Channel Hub

6-channel touch screen hub for temperature display, alarms, configuration and data logging, compatible with PyroMini -BB and -BRT models, as well as PyroMiniBus sensors.

RS485 Modbus master and slave interfaces allow multiple hubs to be connected to a larger network. Optional modules provide analogue and relay outputs.

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

The L-shaped fixed mounting bracket offers a rigid support for the sensor and allows fine rotational adjustment about one axis.

Adjustable Mounting Bracket

The adjustable mounting bracket consists of a fixed mounting bracket plus another L-shaped bracket. When assembled as shown, the adjustable mounting bracket offers a rigid support for the sensor and allows fine two-axis adjustment.

Gooseneck Mount

This stiff, self-supporting steel gooseneck for Calex sensors can be attached securely to machinery via a robust aluminium mounting block.

Simply grab the sensor, move it, and the gooseneck will hold it in position. It is the quickest, easiest way to adjust the aim of the sensor.

Gooseneck Mount Data Sheet (

Laser Sighting Tool

The Laser Sighting Tool screws onto the front of the sensor during installation and shows precisely where the sensor is aiming. Once the sensor has been aimed at the centre of the target and locked in position, the Laser Sighting Tool can be removed. The laser is operated via a latching push button on the front of the tool.

Data Sheet / Operator’s Guide (PDF)

Protective Plastic Window

When fitted over the lens of the sensor, the protective plastic window in stainless steel holder provides mechanical protection and helps retain fragments of lens in case of damage. Adjust the sensor’s emissivity setting to compensate for the presence of the window for maximum accuracy. This accessory is ideal for the food and pharmaceutical industries. Not suitable for short-wavelength PyroMini 2.2 models.

Operator’s Guide – Protective Windows (PDF)

PID Controllers and Indicators

The 4-20 mA output of PyroMini -CB and -CRT models may be connected to any of our indicating controllers for PID control.

The PyroMini is a two-piece sensor with a miniature sensing head and separate electronics module. Each model number includes both parts.

Model Numbers

(click images to enlarge)

General purpose (8-14 µm) PyroMini models

for non-reflective non-metals

Short wavelength (2.0 to 2.6 µm) PyroMini 2.2 models

for improved performance on high-temperature targets and reflective iron or steel surfaces