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Compact MI3 IR Sensor

Raytek® Compact MI3

Big sensor performance in a small sensor package

MI3 Infrarotsensor
MI3M Kommunikationsbox
Raytek MI3 Verteilerbox
Raytek MI3 eigensichere Spannungsversorgung für explosionsgefährdete Bereiche
Raytek MI3100 Messkopf
Screenshot von der DataTemp MultiDrop-Software
MI3 Infrarotsensor
MI3M Kommunikationsbox
Raytek MI3 Verteilerbox
Raytek MI3 eigensichere Spannungsversorgung für explosionsgefährdete Bereiche
Raytek MI3100 Messkopf
Screenshot von der DataTemp MultiDrop-Software

Smart, safe, innovative and versatile solution

  • Assemble your own customized system from a variety of temperature ranges and network communication interfaces
  • Reduce maintenance with self diagnostic features to prevent cable breakage and internal overheating
  • Available with intrinsically safe ATEX / IECEx certification for explosive environments

The Raytek MI3 digital pyrometer features multi-sensor design for OEM applications and process control in continuous noncontact temperature monitoring from -40 to 1800°C (-40 to 3272°F) and offers lowest installation costs per measurement point due to multiple sensing head system design.

  • At a Glance
  • Technical Specs
  • Applications
  • Accessories
  • Resources

The Raytek MI3 digital infrared thermometer represents a new generation of performance and innovation in continuous noncontact temperature monitoring for a broad range of OEM applications and manufacturing processes. Each MI3 infrared temperature thermometer is a two piece system with a miniature sensing head and separate communications electronics. The miniature sensing head can be installed in any system and outperforms much larger sensors, making the Raytek MI3 the best valued IR temperature sensor in its class. 

The OEMMI3 version of this digital infrared thermometer allows direct digital communication with the host machine controller without the need for an additional communication box.

The innovative multiple sensing head interface, which can support up to 8 individually addressable heads per communication box, reduces sensor cost, simplifies sensor installation and applications troubleshooting, and provides the lowest cost per measurement point.

Explosive atmospheres at the workplace can be caused by flammable gases, mists or vapors, or by combustible dust. Raytek MI3 ATEX/IECEx certified sensors can be used safely to monitor the right temperature in such explosive processes. All standard MI3 and MI3100 heads can be ordered with optional ATEX/IECEx certification. One specifically provided Ex-proof power supply can be used with 2 sensing heads.

The MI3 infrared thermometer is also available in a convenient DIN-rail mountable package standard with USB digital communications, as well as RS485, Profibus, Modbus, Profinet and Ethernet options. The DIN mountable communication box supports up to 8 heads and provides 4 galvanic isolated analog outputs.

Key Features:

  • Read temperature ranges from -40 to 1800°C (-40 to 3272°F)
  • Withstand ambient temperatures up to up to 180 °C (356 °F) without cooling
  • Accessories for cooling and air purging
  • Response time: 130 mSec and 20 mSec on on standard models, 10 mSec on MI3100 model
  • Optical resolution: 22:1 on standard models, 100:1 on MI3100 model
  • Dedicated close focus lens for spot sizes down to 0.5 mm (0.02 in)
  • Industrial rugged cable: Silicone and Halogen free, resistant against oil, bases, and acids
  • No cable bending/moving effects, allowing continuous reliable measurement in moving installations (robotic arms, linear drives, chains, etc.)
  • Self diagnostic features: break of a head wire, head internal temperature
  • Plug & Play exchangeability for sensing heads (no heads parameter anymore; Raytek patent)
  • Robust EMI immunity due to digital head-to-box communication
  • DataTemp Multidrop software compatible
  • Sensor status/self diagnostic LED indicator

General Specifications

Model Number
MI3-LT (Low Temp)
MI3-G5 (Glass)
Temperature Range
LTS02, LTS10, LTH10
-40 to 600° °C
(-40 to 1112° ºF)
0 to 1000 ºC
(32 to 1832 ºF)
250 to 1650 ºC
(500 to 3000 ºF)
250 to 1400 ºC
(500 to 2552 ºF)
500 to 1800 ºC
(932 to 3272 ºF)
Spectral Response
8 to 14 μm
5 μm
1.6 μm
1.0 μm
System Accuracy
±1% of reading or ±1°C (2°F)* @23°C ±5°C (73°F ±9°F)
± (0.5% of reading + 2°C)
±0.5% of measured value or ±0.5°C (1°F)*
± (0.25% of reading + 1°C)
Optical Resolution (D:S)
LTS - 2 : 1, 10 : 1, 22 : 1
LTH - 10 : 1, 22 : 1
LTF - 10 : 1
10 : 1
100 : 1
100 : 1
Response Time
LTS, LTH - 130 ms
LTF - 20 ms
130 ms
10 ms
Temperature Coefficient
± 0.05 K / K or ± 0.05% / K of reading*
± 0.01% / K of reading
0.100 to 1.100 for all models
Signal Processing
Peak hold, valley hold, adjustable up to 998 s variable averaging filter

*whichever value is greater

Electrical Specifications - MI3 Box

Outputs 4 – 20 mA, 0 – 20 mA, 0 – 5 V, or 0 – 10 V; J, K, R, or S thermocouple; 0 – 5 V head ambient signal
Thermocouple J: -40 to 600°C (-40 to 1112°F)
K: -40 to 800°C (-40 to 1472°F)
R/S: 250 to 1800°C (482 to 3272°F)
Communications USB 2.0
Profibus DP-V0
Profinet IO
Ethernet TCP/IP, http and 64 MB data logger
Modbus RTU
Power Supply 8 to 32 VDC, 5 W
Environmental Protection IP65 (NEMA 4)



Ambient Temperature LT, G5: -10 to 120 °C (14 to 248 °F)
LTH: -10 to 180 °C (14 to 356 °F)
1M, 2M: 0 to 120 °C (32 to 248 °F)
Laser 1M, 2M: automatic switch off at 65°C (149°F)
Storage Temperature LTH: -20 to 180°C (-4 to 356°F)
all other models: -20 to 120°C (-4 to 248°F)
Environmental Rating IP65 (NEMA-4) / IEC 60529
EMC EN 61326-1:2006


Standards and Compliance

EC Directive 2014/30/EU EMC
EC Directive 2011/35/EU Low Voltage - valid for device: Ex Power Supply xxxMI3ACIS
EC Directive 2011/65/EU RoHS Compliance amended by Directive (EU) 2015/863
EC Directive 2014/34/EU ATEX valid for device: xxxMI3xxxISx, xxxMI330xxxISx, xxxMI3100xxxISx, xxxMI3xxLTHISx, xxxMI3ACIS
EC Directive Nr. 1907/2006 REACH amended by Directive (EU) 2020/2096
EN 61326-1: 2013 Electrical measurement, control and laboratory devices - Electromagnetic susceptibility (EMC)
EN 61558-1: 2006 Safety Requirements for power transformers, power supplies, reactors and similar products (low voltage)
EN 61558-2-6: 2010 Safety Requirements for power transformers, power supplies, reactors and similar products for use up to 1.1 kV (low voltage)
EN 50581: 2012 Technical documentation for the evaluation of electrical products with respect to restriction of hazardous substances (RoHS)
EN 60079-0: 2019 Risk of explosion – part 0: general requirements (ATEX)
EN 60079-11: 2012 Risk of explosion – part 11: device protection by intrinsic safety “I” (ATEX)
UKCA Conforms to UK Conformity. Except for units with intrinsically-safe rating.
KCC Electromagnetic Compatibility applies to use in Korea. This product meets requirements for industrial (Class A) electromagnetic wave equipment.

Compact MI3 pyrometers can be used across numerous industries and are ideal for a variety of OEM and end-user manufacturing applications including the list below and many others.

Click here if you would like to speak with an expert to discuss your application

Each MI3 sensor system is comprised of (1) MI3 sensing head and (1) MI3COMM or MI3MCOMM communication module. The sensing head includes one mounting nut and 1m (3.3ft) cable. Longer cables up to 30 m (100ft) maximum are available and must be specified at time of order. The MI3 sensing head and MI3COMM box are ordered as separate items. Additional accessories are listed below:

Accessories for MI3 Sensing Heads
  • Adjustable Bracket (LT, G5: XXXMIACAB / 1M, 2M: XXXMI3100ADJB)
  • Fixed Bracket (LT, G5: XXXMIACFB / 1M, 2M: XXXMI3100FB)
  • Isolation Kit for Fixed Bracket (1M, 2M: XXXMI3100ISOKIT)
  • Air Purge (LT, G5: XXXMIACAJ / 1M, 2M: XXXMI3100AP)
  • Air Cooling Jacket (XXXMIACCJ: 0.8 m/2.6 ft, XXXMIACCJ1: 2.8 m/9.2 ft)for ambient temperatures up to 200°C/392°F (LT, G5 only)
  • Close Focus Lens (LT, G5: XXXMI3ACCFL))
  • Protective Window (LT, G5: XXXMIACPW / 1M, 2M: XXXMI3100PW)
  • *Optional longer head cable lengths: 3 m, 8 m, 15 m, 30 m (9.8, 26, 49, 98 ft.)
  • *Optional water cooled housing (1M, 2M heads)
  • *Optional Networkable OEM sensing head without the need for a box


Accessories for MI3 Box
  • Multi-Channel Box to support up to 8 sensing heads in a network (XXXMICONNBOX)
  • USB/RS485 Adapter for boxes with RS485 interface (XXXUSB485)
  • *Optional Fieldbuses for Comm Box: RS485, Profibus, Profinet, Ethernet, Modbus
  • *Optional 4 analog output channels for Comm Box, DIN 6TE: mA or V, all channels electrically isolated
*Options must be specified at time of order
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