Calex FM2.2-301-MT-CRT-3M, FM2.2-301-MT-BRT-3M, FM2.2-301-MT-CRT-5M, FM2.2-301-MT-CRT-10M, FM2.2-301-MT-BRT-5M Operator's Manual

FibreMini

Fibre Optic Pyrometer

Operator's Guide

FibreMini

The FibreMini is an infrared temperature sensor (pyrometer) with a fibre optic sensing head

and separate electronics module.

The fibre optic sensing head withstands ambient temperatures of up to 200°C and contains no

electronics, so it may be used in areas of strong electromagnetic interference.

Continuous laser sighting illuminates the position and size of the measurement spot while

readings are being taken, without affecting the accuracy of the measurement.

A touch screen interface is built into the electronics module, with temperature display, sensor

configuration, data logging to optional MicroSD Card, and configurable alarm relay outputs.

The sensor works by detecting the infrared radiation emitted from a surface as a result of its
own temperature. The amount of radiation emitted is related to the temperature, and the

sensor uses this relationship to provide an accurate temperature output.

FibreMini sensors are ideal for measuring the surface temperature of many reflective metals in

high-temperature applications, including iron and steel, as well as non-reflective non-metals.

Specifications

Measurement Specifications

Temperature Range

MT models: 250°C to 1000°C
HT models: 450°C to 2000°C

Max. Temperature Span for 4-20

mA Output (-CRT models)

Full temperature range (up to 1550°C)

Min. Temperature Span for 4-20

mA Output (-CRT models)

100°C

Output

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 narrow-angle optics (see

Field of View Diagrams below)

Accuracy

±1% of reading

Repeatability

±0.5% of reading

Emissivity Setting

Adjustable, 0.10 to 1.00

Emissivity Setting Method

-BRT models: via RS485 Modbus

-CRT and -BRT models: via touch screen

Response Time, t90

≥240 ms (90% response)

Spectral Range

2.0 to 2.6 μm

Supply Voltage

24 V DC ± 5%

Max. 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, electronics module temperature,
max, min, average, emissivity setting, reflected energy

compensation temperature, alarm events

File format

.csv

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

0.1°

Alarm Configuration

Two alarms with adjustable level, individually
configurable as HI or LO.

Signal Processing

Average, peak hold, valley hold, minimum, maximum

Mechanical Specifications

Sensing Head

Electronics Module

Construction

Stainless Steel 316

Die Cast Aluminium

Major

Dimensions

12 (dia.) x 48 (l) mm

98(w) x 64(h) x 36(d) mm

Mounting

M12 x 1.5 mm thread

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

This product is CE marked and RoHS compliant.

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.

Model Numbers

FM2.2 - 301 - MT - CRT - 3M

Fibre Optic
Cable Length

3M = 3 metres
5M = 5 metres
10M = 10 metres

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

Temperature Range
MT = 250°C to 1000°C
HT = 450°C to 2000°C

Field of View
301 = 30:1 divergent optics
751 = 75:1 divergent optics

Series
FM2.2 = FibreMini pyrometer with 2.2 µm spectral response

Field of View Diagrams

Diagrams show the diameter of the measured spot at each distance, for 90% energy.
The sensor will also measure at longer distances than the diagrams show.

Measurement accuracy is not affected by distance, however the measured spot size will be

larger at longer distances.

Emissivity Adjustment

The default emissivity setting is 0.95. This may be adjusted via the touch screen interface:

Settings  Emissivity & Compensation

Enter the emissivity of the target surface here. For more information on how to find the target

emissivity, contact Calex.

Reflected Energy Compensation

Settings  Emissivity & Compensation

Some of the infrared energy detected by an infrared temperature sensor is not emitted by the

target, but is a reflection of its surroundings.

To ensure an accurate reading, the sensor needs to know the temperature of the source of
that reflected energy. In most applications, the surfaces that surround the target have the
same temperature as the sensor itself (e.g. the sensor and target are in the same room). The
sensor automatically compensates for the reflected energy, so this setting is not required and

should be switched off.

However, in some applications, the source of the reflected energy (the surroundings of the
target) is much hotter or colder than the sensor itself. In these cases, Reflected Energy

Compensation should be enabled and set to the temperature of the surroundings of the target.

For example: if the target is inside a furnace and the sensor is outside, the reflected energy is
coming from the inner walls of the furnace. Enter the furnace temperature into “Reflected

Temperature” and select “Enable Reflected Energy Compensation”.
For assistance, contact Calex.

Alarm Outputs

The sensor has two alarm relay outputs, rated 24 V DC, 1 A. They are individually
configurable via the touch screen interface.

Each alarm can be configured as Low or High, with set point and hysteresis.
For more information, see “Alarms”.

Touch Screen Interface

The backlit touch screen interface provides a large, bright display of the measured

temperature, two alarm relay outputs, and options for full configuration of the sensor.