FLIR MR40 - Moisture Pen + Flashlight | FLIR Systems  
FLIR MR40 - Moisture Pen + Flashlight | FLIR Systems

Moisture Pen + Flashlight

The FLIR MR40 is a pocket-portable, rugged 2-pin, single-scale moisture meter with an integrated flashlight for wood and common building materials – ideal for builders, building inspectors, remodelers, moisture remediation technicians, pest control professionals, and residential roofing and flooring contractors. Providing reliable and accurate measurements offered at a highly affordable price point, MR40 is a quick and easy-to-use tool to find and quantify moisture content.

When used in combination with a thermal camera, MR40 can help confirm whether a cold spot in a thermal image is moisture, and measure the severity of the problem.


Easy to use

Equipped with a clear LCD display, a simple On/Off button with 'Auto Power Off', replaceable pins, and an audible indication of measured range, the MR40 is a simple and effective tool for reliable measurements.



Convenient, portable, rugged design

The MR40 is small enough to carry in your pocket, IP54 splash-proof rated, and 3-meter drop tested, so it's always ready to work when — and wherever— you are.



Reliable and accurate measurements

The MR40 has all the essential features you need to quickly verify moisture and determine the severity of the problem including a measurement 'hold' function and calibration/pin check integrated in the cap.


FLIR MR40 Features


Moisture pen + flashlight

Single-scale moisture meter and flashlight

Pocket portable

MR40 fits in your pocket to easily carry with you

Icon - Worklights

Simple and reliable

All the features you need including Measurement ‘Hold’, Calibration/Pin Check, and audible indication of measured range

Icon - Durable


Drop-tested and IP rated for water resistance

Icon - Bluetooth

Replaceable Pins

Includes two sets of pins


Includes Limited Lifetime Warranty

FLIR MR40 Specifications

Measurement Range 5% to 60% MC (moisture content)
Measurement Accuracy 5 to 30% MC (Moisture Content): +/- 2%
30- 60% MC (Moisture content): Reference only
Note: For materials other than Group9/ Building Materials: plywood, drywall, and oriented strand board (OSB), download the MR40 Material Conversion Table (publication MR40-AN01):
Audible Indication 5-12%: Low Beep rate. 13-60%: Higher beep rate.
More than 60%: Highest Beep rate (Display OL)
Calibration/ Pin Check, Integrated in Cap 16%
Meter data
Work light ~40 lumens
Display LCD
Electrode pins Integrated, Replaceable
Measurement Principle Electrical Resistance
Warranty Limited Lifetime
Calibration cycle N/A
Certifications CE
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Power system
Power requirements 2 × AAA alkaline batteries
Battery life 70 Hrs w/o Flashlight
Battery status indicator 4 Bar battery icon
Auto Power Off (APO) 3 minutes
Environmental Data
Drop test 3 m (9.8 ft.)
Ingress Protection Rating IP54 Splash Proof
Operating temperature -10 to 60°C (14 to 140°F)
Physical data
Weight 80g (2.8 oz) with Battery
Dimensions (H × W × L) 193 x 26 x 31 mm (7.6" x 1.0" x 1.2")
Material PC-ABS w/TPE Overmold
Color Gray, black

Product Literature

MR40 Datasheet


Call 1-866-477-3687 to chat with a knowledgeable specialist.

Find a Distributor

For other options to buy, please visit a
FLIR Authorized Distributor

Buy with Confidence

All products are FLIR Factory Certified and come with a full warranty.