Digital Moisture Meter Calibration for Accuracy in Home Inspections

Digital Moisture Meter Calibration

At the launch pad, the latest NASA rocket sits waiting to head into space. 

For the better part of the last year, engineers and scientists have worked round-the-clock to make sure humankind’s next off-planet trip is one that’s successful, safe, and fruitful. 

Long before astronauts set foot in the ship and the launch sequence is primed, those assigned to the mission have made sure the spacecraft’s gauges, meters, and equipment are calibrated. 

A testing and verification process, calibration ensures measuring equipment is working properly and taking accurate readings. 

While surveying for moisture in a home is a far cry from going into space, the quality of an inspection is largely dependent on having tools that work as they’re supposed to -- moisture meters included. 

Think of it as routine maintenance -- regular digital moisture meter calibration checks that the device is functioning without issue and taking readings that aren’t questionable

Digital Moisture Meter Calibration: A User’s Guide

Though moisture meter calibration may sound like a process that’s extensive and time consuming, the simple fact is it’s not. 

Checking the calibration of your moisture meter doesn’t require any specialized training, regardless of the type of meter you’re using. The vast majority of moisture meters can be checked in the field. 

Pin-Type Meter Calibration 

Pin-type meters are made to measure actual moisture content within a material. They do so by measuring electrical resistance between its pin-like probes. 

Calibrating a pin-type meter is easy, and most come with a calibration device -- a moisture content standard (MCS) -- designed specifically for your meter to measure resistance.

To check the calibration of your pin-type meter, simply touch its pins to the contact points on the MCS and wait a few seconds. Your meter should display a reading for a wood moisture equivalency of +/- 18% (in Protimeter Instruments). If your reading is outside that range, there’s likely an issue affecting your meter’s ability to take accurate measurements -- perhaps its pins are dirty or it’s malfunctioning.

Pinless Moisture Meter Calibration

A noninvasive device, pinless moisture meters confirm moisture within a material. Using radio frequencies, pinless meters assess average moisture content within their depth of measurement.

 Like pin-type moisture meters, checking the calibration for a pinless moisture meter is a quick and easy process. 

After you’ve turned the meter on, place your hand on its contact plate. You should see a reading of 999 after a few seconds. When holding the meter in the air and taking a reading, it should display a reading of 0% or three dashes. 

Some pinless moisture meters come with a sensor calibration block -- a small, solid box the meter makes contact with. If you’re using a sensor calibration block, use one that’s made for your meter -- using blocks designed for other meters may give inaccurate results. 

Some of the latest Protimeter instruments, such as the ReachMaster Pro and the Protimeter MMS2, allow the user to recalibrate the meter through the menu options. 

Certified Digital Moisture Meter Calibration

Not all digital moisture meter calibration happens by the user. Some moisture meters have special certification by the International Organization for Standardization (ISO), meaning they meet high-level performance standards. 

To maintain this certification, your moisture meter will need to be sent out for independent calibration annually. After receiving rigorous testing, your meter is given a moisture meter calibration certificate. 

Verifying Moisture Meter Calibration

Regardless of the type of moisture meter you’re using, it’s always a good idea to double-check that it’s calibrated and functioning correctly before using it in a home inspection. 

Verifying calibration can be done quickly by taking measurements with your meter and comparing readings from a second, identical meter testing the same materials or spots. As long as the readings are identical, your meter is calibrated and ready to tackle a home moisture inspection. 

With non-penetrating (pinless) moisture meters, testing a material for moisture content also helps confirm calibration was successful. If the material is damp, a pinless moisture meter will confirm the presence of moisture. 

Digital Moisture Meter Calibration = Peace of Mind 

Like an astronaut on the verge of making an incredible discovery, having tools that take readings correctly is critical for a home moisture inspection. By taking a few moments for digital moisture meter calibration, you’ll have the peace of mind that you’re ready to launch your survey.

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