Starting at $325.00

3 in stock. View available part numbers.

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  • Compatible with Raytek MI3 electronics modules
  • Temperature range:
  • LT: -40 to 600°C or 0 to 1000°C
    • G5: 250 to 1650°C
  • Spectral response:
    • LT: 8 to 14 microns
    • G5: 5 microns
  • Accuracy: ±1% of readings
  • Optical resolution: 2:1, 10:1 or 22:1
  • Emissivity: 0.100 to 1.000 (digitally adjustable in .001 increments)
  • Transmission: 0.100 to 1.000 (digitally adjustable in .001 increments)
  • Rugged stainless steel construction
  • ATEX and IECEx-proof for dust and gas atmospheres version available

The Raytek MI3 infrared thermometer is a two-piece system with miniature sensing head and separate communications electronics. Designed for a wide range of applications, the MI3 is accurate, rugged, affordable, and easy-to-install and operate. With the MI3, precision infrared temperature measurement is now an economical alternative.

The Raytek MI3 sensing heads are designed for an endless range of applications and feature a variety of sensing head options. Thanks to precision, high-resolution silicon optics, the MI3 sensors provide a range of optical resolutions including 2:1, 10:1 and 22:1. The MI3 sensing heads are also available in two versions. The LT version has a temperature range of -40 to 600°C or 0 to 1000°C and a spectral response of 8 to 14 microns. The LT also has a fast-response option for response times as fast as 20 mSec. The G5 version has a temperature range of 250 to 1650°C with a spectral response of 5 microns. The basic accuracy for both versions is ±1% of readings.

All sensor-operating parameters are easily accessed and configured through the standard user interface with large backlit LCD display, or with the powerful Raytek DataTemp® multidrop software via the USB 2.0 digital interface. Standard functions of the MI3 system include: adjustable emissivity, transmissivity, peak hold, valley hold and signal averaging; and configurable inputs for emissivity control, ambient background compensation and trigger/hold input.

The MI3's miniature size and low cost per measurement point make it ideal for installation at multiple points in your process. The innovative multiple sensing head interface supports up to 8 individually addressable heads per communication module which reduces overall cost while simplifying installation and troubleshooting. The rugged stainless steel sensing head ensures reliable long term performance in the harshest industrial environments.

Raytek MI3 sensing heads ship complete with one mounting nut.

Required Components

These additional components are required for the operation of your product. We strongly advise you to purchase these components unless you already own them or own a suitable alternative.

Raytek MI3 Electronics Modules
Electronics module with communications, output and LDC display for use with the Raytek MI3 sensor head
In Stock
Raytek MI Series Adjustable Mounting Bracket
Adjustable bracket for the Raytek MI3 and MI Series Sensors
In Stock
Raytek Ex-Power Supply
ATEX Ex power supply box, with 16.4ft (5m) long cable, that supports up to 2 intrinsically safe MI3 heads

Air Purge

Raytek MI series air purge jacket (no cooling)
Air purge jacket (no cooling) for Raytek Thermalert MID or GPM series
In Stock
Raytek MI Series Air Hose
Air cooling & purging system with 2.8' (0.8m) air hose for MID or GPM series
In Stock
Raytek MI series air cooling & purging system including 9.2' (2.8m) air hose
Air cooling & purging system with 9.2' (2.8m) air hose for MID or GPM series

Mounting Bracket

Raytek MI series extra mounting nuts
Raytek MI series extra mounting nuts
In Stock
Raytek MI Series Fixed Mounting Bracket
Fixed bracket for the Raytek Thermalert MID or GPM series

Viewing Windows/Protection

Raytek MI Series Zinc Sulfide Protective Window
Raytek MI Series Zinc Sulfide Protective Window
Raytek MI Series Polymer Protective Window
Polymer Protective Window for Raytek MI3 Sensors
In Stock


Please consider these optional accessories.

Raytek XXXMIACRAJ Right Angle Mirror
Raytek MI series right angle mirror for use with air cooling and/or purging
Raytek XXXMIACRAJ1 Right Angle Mirror
Raytek MI series right angle mirror for use with air purging (no cooling)
Raytek MI Series Close Focus Lens
Close focus lens for Raytek MI3 sensors (10mm focus distance)
Raytek MI3 & MI3M Series Interface Box
Multi-channel sensor interface box for Raytek MI3 and MI3M Series instruments

Application Notes

Here's how some of our customers used this product.

Monitoring Road Temperature to Optimize the Application of Salt

The Background: A municipality wishes to measure pavement temperatures as a means of optimizing the application of salt to snowy and icy roads.

The Problem: The surface temperature of a snow- or ice-covered road determines the amount of salt needed. As temperatures go down, the amount of salt needed to melt a given quantity of ice increases significantly. Applying salt is expensive and it is important to optimize the amount used since under-salting creates public safety hazards while over-salting may have a negative environmental impact.

The Solution: Raytek MI3 Infrared Temperature Sensors mounted to the outside of the salt trucks provides accurate, real-time, non-contact measurement of pavement temperature while the truck is moving. The electronics module mounts conveniently inside the cab making is as easy as possible to tailor salt amounts to road conditions.

Part Number Price Available
Show Configuration
Base Price
Ambient Temperature
Range: -40 to 600°C, Spectral Range: 8-14µm, D:S=10:1; Response: 130ms
Intrinsic Safety
Not Intrinsically Safe
Cable Length
3 meters (+$25.00)
$350.00 3

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