Fibre Optic Pyrometer for Harsh Applications (Discontinued)
Alternative Product:PyroMini


  • Temperature ranges from 250°C to 2000°C
  • Miniature sensing head withstands 200°C ambient temperature
  • Short measurement wavelength for improved accuracy on metals
  • No electronics in the sensing head - ideal for use near induction heaters and strong electromagnetic fields
  • Choice of analogue or digital output; alarm relays on all models
  • Built-in laser sighting

The FibreMini is an industrial pyrometer with a fibre optic sensing head and a separate electronics module with touch screen interface.

The sensing head is designed to withstand high ambient temperatures of up to 200°C without cooling. This pyrometer is ideal for target materials including steel, iron and carbon, as well as other metals and non-metals.

General Specifications

Temperature Range
MT models: 250°C to 1000°C
HT models: 450°C to 2000°C
Max. Temperature Span (-CRT models)
Full temperature range (up to 1550°C)
Min. Temperature Span (-CRT models)
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)
±1% of reading
±0.5% of reading
Emissivity Setting
0.10 to 1.00 for measurements between 250°C to 350°C
0.05 to 1.00 for measurements above 350°C
Emissivity Setting Method
-BRT models: via RS485 Modbus
-CRT and -BRT models: via touch screen
Response Time, t90
125 ms (90% response)
Spectral Range
2.0 to 2.6 μm
Supply Voltage
24 V DC ± 5%
Maximum Current Draw
100 mA
Max. Loop Impedance (-CRT models)
900 Ω (4-20 mA output)
Alarm Relays
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)
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 diameter contains 90% of the energy detected by the sensor. For maximum accuracy, we normally recommend the target is at least twice as large as the given measured spot. The sensor may be used at longer distances than shown above. In clean air there is no maximum measurement distance, and the distance does not affect the sensor's measurement accuracy; this is because the FibreMini is filtered to detect only the wavelengths of IR 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)
12(dia.) x 48(l) mm (see Installation)
Major Dimensions (Electronics Module)
98(w) x 64(h) x 36(d) mm
Mounting (Sensing Head)
M12 x 1.5 mm thread
Mounting (Electronics Module)
Requires two M4 screws for wall mounting (see Installation)
Fibre Optic Cable Length (sensing head to electronics module)
3 m, 5 m or 10 m
Cable Connections
Removable screw terminal blocks (see "Connections")
Conductor size: 28 AWG to 18 AWG
Output Cable Gland
Suitable for cable diameters 3.0 to 6.5 mm

Environmental Specifications

Sensing Head Electronics Module
Environmental Rating IP65 (NEMA 4)
Ambient Temperature Range 0°C to 200°C 0°C to 60°C
Relative Humidity Maximum 95% non-condensing Maximum 95% non-condensing
CE Marked Yes Yes
RoHS Compliant Yes Yes

Electromagnetic Compatibility Standards

Conforms to EMC Directive EN61326-1:2006 (Electrical equipment for measurement, control and laboratory use – Industrial) as well as industrial standards for electromagnetic immunity and emissions.

The FibreMini is ideal for use where the ambient temperature is high, and/or the target has a reflective metal surface. The following suggestions are just a few of the industrial applications where the FibreMini can be used.

Typical Applications

Iron & Steel
The harsh high-temperature environments near furnaces in the metals industry require rugged measurement equipment.

The sensing head and fibre optic cable of the FibreMini can be placed in ambient temperatures of up to 200°C, and they are small and flexible enough to be fed through protective conduit with very tight bends.

The touch screen interface can be operated with gloves on, and used as a local display, while still transmitting the temperature back to the control room.
Pipe Welding
Measure the preheat temperature of steel pipes before welding, between the induction coils. For measuring temperatures below 250°C in this application, please see the PyroUSB 2.2.
Aluminium Extrusion
The FibreMini produced good results at the press exit of an aluminium extrusion line, where the surface of the aluminium profile was repeatable and the emissivity was found to be consistent. Special considerations normally apply to aluminium temperature measurement, however it is possible to achieve good results with single-wavelength sensors such as the FibreMini in situations where the emissivity and temperature are both repeatable.

In this application, the PyroCube M was also used for measuring the profile temperature after the water quench.

Electrical Installation

PM180 6-Channel Hub

6-channel touch screen hub for temperature display, alarms, configuration and data logging, compatible with PyroMini, PyroBus, PyroMiniBus and FibreMini sensors. Isolated RS485 Modbus master and slave interfaces allow multiple hubs to be connected to a larger network. Optional modules provide analogue and relay outputs.

Panel Mounting Kit

The Panel Mounting Kit (PMK) is an ABS plastic assembly that allows the FibreMini’s touch screen display module to be fitted to a panel.

The PMK is compatible with panels up to 5 mm thick.

PID Controllers and Indicators

The 4-20 mA output of PyroMini 2.2 -CB and -CRT models may be connected to any of our indicating controllers for PID control.

Air Purge Collar

The FibreMini air purge collar helps keep the lens of the sensing head dry and free of dust when used with a continuous supply of clean air.

Mounting Bracket

The fixed and adjustable mounting brackets provide a secure fixing point for the sensing head, and allow rotation about 1 or 2 axes.

Model Number


Series FM2.2 FibreMini pyrometer with 2.2 µm spectral response, miniature sensing head on fibre optic cable, built-in laser sighting, electronics module with 2 alarm relay outputs and touch screen interface
Field of View 301 30:1 divergent optics
751 75:1 divergent optics
Temperature Range MT 250°C to 1000°C
HT 450°C to 2000°C
Output and Interface CRT 4-20 mA output, two alarm relay outputs, with touch screen
BRT RS485 Modbus output, two alarm relay outputs, with touch screen
Fibre Optic Cable Length 3M 3 metres
5 metres
10 metres

    The FibreMini's interface is very similar to the PyroMini. These videos show the PyroMini interface: