General Tools & Instruments MMD5NP Instruction Manual
Please read this manual carefully and thoroughly before using this product.
PINLESS
LCD MOISTURE METER
USER’S MANUAL
MMD5NP
MMD5NP Manual_FINAL_051811_Layout 1 5/18/11 11:12 AM Page 1
2
TABLE OF CONTENTS
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 3 –4
Key Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
What’s in the Blister Pack . . . . . . . . . . . . . . . . . . 5
Product Overview . . . . . . . . . . . . . . . . . . . . . . . . . 5
Setup Instructions . . . . . . . . . . . . . . . . . . . . . 6 –7
Install Battery . . . . . . . . . . . . . . . . . . . . . . . . . 6
Operating Instructions . . . . . . . . . . . . . . . . . . 6 –7
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Warranty Information . . . . . . . . . . . . . . . . . . . . . . 9
Return for Repair Policy . . . . . . . . . . . . . . . . . . . 10
MMD5NP Manual_FINAL_051811_Layout 1 5/18/11 11:12 AM Page 2
3
INTRODUCTION
Thank you for purchasing General Tools & Instruments’
MMD5NP Pinless LCD Moisture Meter. Please read this user’s
manual carefully and thoroughly before using the meter.
The MMD5NP is a non-invasive (pinless) instrument that can
detect moisture up to 3/4 in. (20mm) below the surface of
wood or building material (concrete, bricks, wallboard, etc.).
The meter infers the level of moisture from the material’s
capacitance, which the meter reads by measuring its effect
on an electric field it generates every time it is powered on.
The meter exploits two physical phenomena to make its
measurements:
1. The linear relationship between a solid material’s moisture
level and its dielectric constant—and therefore its
capacitance.
2. The so-called fringe-field effect—the slight spreading of the
electric field produced by current flow between two electrodes
when both electrodes are on the same side of a material.
Behind the back cover of the MMD5NP are two metal plates.
When the meter is powered on, the plates are given small and
opposite charges. The potential difference causes current to
flow, creating a three-dimensional electric field.
When the back of the meter is placed against one side of a
material with moisture on or slightly below its surface, the
increased capacitance of the material distorts the electric
field to an extent that can be sensed (as a change in flux over
the sensing area) and measured. Displayed readings reflect
the average moisture level of the material between its surface
and the electric field’s maximum penetration of 3/4 in.
Moisture closer to the surface has a greater effect on the
reading than moisture at the maximum penetration depth.
MMD5NP Manual_FINAL_051811_Layout 1 5/18/11 11:12 AM Page 3
The MMD5NP has been calibrated at the factory for use with
wood and building material (concrete, bricks, wallboard, etc.).
Because the capacitance of wood and the capacitance of
building material are affected differently by moisture, the
meter measures their moisture content on different scales.
A button on the front of the MMD5NP provides a convenient
way to switch between the two materials. Display icons
indicate which material is being tested, as well as whether
the current reading is considered low, medium or high for the
material. Any reading can be held by pushing another frontpanel button; this feature makes it possible to make a
measurement in a dark place and display it after bringing the
meter into a lighted area. The meter also is equipped with a
buzzer whose tone rises with increasing wetness; this feature
makes it easy to detect areas of peak moisture.
The MMD5NP is powered by a 9V battery included in the
blister pack.
KEY FEATURES
• Non-invasive/non-destructive measurement technique
• Jumbo display
• Wide measurement range
• Intuitive display icons: Low/medium/high moisture content;
wood/building material mode
• Measurement hold function
• Audible peak reading alert
• Auto-calibrating
• Auto power off
• Low and very low battery warnings
4
MMD5NP Manual_FINAL_051811_Layout 1 5/18/11 11:12 AM Page 4