General MMD8P User manual

PRECISION MULTI-SPECIES
WOOD MOISTURE METER
USER’S MANUAL
MMD8P
Please read this manual carefully and thoroughly before using this product.

TABLE OF CONTENTS
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Key Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 – 3
What’s in the Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Product Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Setu Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 – 5
Install Battery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Advanced Setu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 – 5
O erating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 – 10
Select a Dis lay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 – 7
Select a S ecies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 – 8
Making Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Storing Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 – 9
Recalling and Deleting Records. . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Com ensating for Tem erature . . . . . . . . . . . . . . . . . . . . . . . . 9 – 10
S ecifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 – 11
O erating & Maintenance Ti s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Warranty Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 – 12
Return for Re air Policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
INTRODUCTION
Thank you for purchasing General Tools & Instruments’ MMD8P Precision Multi-Species Woo
Moisture Meter. Please rea this user’s manual carefully an thoroughly before using the meter.
The MMD8P is tailore for use in woo working an lumber purchasing. Examples inclu e:
• Measuring the moisture content of woo before painting, wallpapering, sealing,
treating or joining
• Selecting ry lumber
The meter infers the moisture level of a piece of woo by measuring the electrical resistance it
presents between the meter’s test pins. The electrical resistance of any material can be use as
a proxy for its moisture level. The wetter a material, the lower its resistance.
The measurements ma e by the MMD8P mostly represent surface moisture content because:
1) Moisture close to the surface has a greater effect on a rea ing than moisture eep below it;
an 2) At a length of 0.2 in. (5mm), the pins at the top of the MMD8P are too short to be riven
eep into a har material.
KEY FEATURES
• Rea ings are species-specific, erive from in ustry-stan ar moisture-resistance
curves for 48 popular species of woo
• Joystick makes species selection fast an easy
• Also measures an isplays ambient temperature (in °F or °C) an RH
• Measurements can be compensate for ambient temperature, improving precision
• Super-bright yellow OLED (organic light-emitting io e) ot matrix isplay
2

• 99 recor memory with manual or automatic (time-base ) recor ing
• Multiple isplay options, inclu ing analog bar graph
• Measurement hol button
• Au ible moisture alarm
• Pin cover oubles as calibration checker
• Replaceable pins
• Auto power off function (can be isable ) with a justable “time-out” trigger
• Separate in ications of remaining battery charge an low battery charge
• 1 year limite warranty
WHAT’S IN THE PACKAGE
The MMD8P comes in a custom har carrying case insi e a white box along with a “9V” battery
an this user’s manual.
PRODUCT OVERVIEW
The figure shows all of the controls, in icators an physical features on the front, top an back of
the MMD8P. Familiarize yourself with their positions an functions before moving on to the Setup
Instructions an Operating Instructions.
3
(MR MC) MULTI-FUNCTION
BUTTON
1. PRESS AND HOLD TO POWER METER
ON & OFF
2. PRESS BRIEFLY TO HOLD READING
3. PRESSED IN MEMORY STORE MODE,
STORES DISPLAYED RECORD
4. PRESSED IN MEMORY VIEW MODE,
DELETES DISPLAYED RECORD
5. PRESSED IN TEMPERATURE
COMPENSATION MODE, SAVES
SELECTED TEMPERATURE
OLED DISPLAY
PIN COVER
JOYSTICK
BATTERY COMPARTMENT
(ON BACK OF METER)
CALIBRATION
CHECK HOLES
TEMPERATURE
& RH SENSORS
MODE (SELECT) MULTI-FUNCTION BUTTON
IN REAL-TIME MEASUREMENT MODE (WITH
INITIAL DIGITAL DISPLAY):
1. PRESSED ONCE, SWITCHES TO ANALOG BAR
GRAPH DISPLAY
2. PRESSED AGAIN, SWITCHES TO FULL-SCREEN
DISPLAY OF MOISTURE LEVEL READING
3. PRESSED AGAIN, SWITCHES TO DISPLAY OF
MOISTURE LEVEL READING ABOVE AMBIENT
RH AND TEMPERATURE READINGS
4. PRESSED AGAIN, SWITCHES TO MEMORY
STORE MODE
5. PRESSED AGAIN, SWITCHES TO MEMORY
VIEW MODE
6. PRESSED AGAIN, SWITCHES TO
TEMPERATURE COMPENSATION SET MODE
7. PRESSED AGAIN, SWITCHES TO DISPLAY OF
REMAINING BATTERY CHARGE
8. PRESSED AGAIN, SWITCHES BACK TO INITIAL
DIGITAL DISPLAY
PRESSED IN MEMORY STORE, MEMORY VIEW
AND TEMPERATURE COMPENSATION SET
MODES, ADVANCES TO NEXT DISPLAY MODE
TEST PINS
FULL 66% 33% LOW BATTERY

SETUP INSTRUCTIONS
INSTALL BATTERY
To open the battery compartment, turn the meter over an lift the tab on the bottom of the
battery compartment cover. Remove the cover an set it asi e. Then plug the inclu e “9V”
battery into the wire socket insi e the compartment. The terminals of the battery an the socket
mate in only one way, with the smaller male terminal plugging into the larger female terminal.
Close the battery compartment by replacing its cover an snapping it shut.
ADVANCED SETUP
Before using the meter, General recommen s that you a just five operating an “housekeeping”
parameters to your preferences. They are:
1. The Auto Power Off (APO) “time out” trigger point, an whether the function is enable
2. The low threshol of the moisture level alarm (beeper), an whether the alarm is
enable
3. Whether the meter’s memory is activate , an if so the number of moisture-
measurement recor s to provi e space for
4. Whether recor s are store manually or automatically. If automatic storage is chosen,
how often rea ings are store
5. The temperature measurement unit (°F or °C)
It is not necessary to enter A vance Setup mo e if you are willing to use the efault settings for
each of the above five parameters. The efault settings are:
1. APO:
ON , with a 2-minute “time out” trigger point (2 minutes of inactivity at the front-
panel buttons)
2. Moisture alarm:
OFF
3. Memory storage: OFF
4. Memory timer: MANUAL
5. Temperature unit: °F
To enter Advanced Setup mode
, power on the meter in a special way by pressing an hol ing the
MODE button as you press an hol the button. The following setup screen will appear,
showing the efault settings. On the right si e of the top (APO) line,
2Mins. will initially be
flashing.
SETTIN
APO. 2Mins.
Alarm OFF
Store Mem. OFF
Mem. Timer MANUAL
Temp Unit °F
EXIT
To change any of these operating an housekeeping settings:
A. Navigate to its line by pressing the ▲an ▼pa s of the joystick ( button). When a
setting is rea y to be change , it will begin to flash.
B. Use the an /or pa s to select a new value.
C. Press the
MODE button to save the selection (or selections, if you change more than
one setting), exit A vance Setup Mo e, an enter real-time measurement mo e.
4

Following are the setting options for each of the five parameters:
1.
APO: OFF , or 1 to 99 minutes of front-panel inactivity, in 1-minute increments. Be
aware that by isabling the APO function, you run the risk of ischarging the meter’s
battery if you forget to power the meter off each time you finish using it.
2. Alarm: OFF , or a repeating beep for any moisture rea ing above a threshol of 0.1 to
99.9% WME, in increments of 0.1%
3.
Store Mem.: OFF , or 1 to 100 memory recor s, in 1-recor increments. As a practical
matter, there is no reason
not to enable memory storage, an no reason not to select
the maximum memory capacity available—100 recor s.
4.
Mem. Timer: MANUAL (on-screen recor s can be store manually—by pressing the
(MR MC) button)—or automatically at a sampling rate from once per secon to
once every 99 secon s, in 1-secon increments. During setup, these automatic
storage options appear on-screen as
1s(AUTO) , 2s(AUTO) , etc. through 99s(AUTO) .
5. T
emp Unit: °F or °C
A vance Setup Hints:
• Pressing an hol ing the or pa for more than 5 secon s increases the
increment of change from one igit to 10 or more. Doing so can make it faster to
make a change to a new value far from an ol one.
• You can use the an pa s to “wrap aroun ” the low or high en of a setting
range, making it faster to ial up a new value for selection. For example, pressing the
pa four times with the APO trigger showing
2Mins. woul pro uce the following
isplays in turn:
1Min. , OFF, 99Mins an 98Mins.
• When pressing the an pa s, be sure not to apply any vertical force. If the
joystick etects any vertical force, the meter’s firmware will assume that you want to
switch to the parameter above or below the one currently flashing.
Once you have reset any or all of the five parameters, remember to press the MODE button to
save your selection(s), exit A vance Setup Mo e, an enter real-time measurement mo e with
the Full Measurement Screen (see next section) on the OLED.
OPERATING INSTRUCTIONS
To power on the meter, press the button an hol it for at least three secon s.
(To power off the meter, follow the same instruction.)
You will know that the meter has powere on when
you see the “welcome” screen at right.
Two secon s after it appears, the welcome screen
will be replace by the screen at right,
(which in icates remaining battery charge)
for 2 secon s.
5

After 2 secon s, the battery-charge screen will be replace by the screen irectly below—the
first of four measurement isplay options.
On this screen, note:
• The number of the selecte woo species at upper left
• The species name at its right
• An icon representing the remaining battery charge at upper
right
• The currently measure moisture level in the center of the
screen. (On the screen shown,
99.9%WME shoul not be
mistaken for an actual rea ing; rather, it in icates any
rea ing above the meter’s maximum measurement level
of 40%WME.)
• The current relative humi ity (RH) percentage at lower left
• The current ambient temperature (
TA. ) at lower right
SELECT A DISPLAY
The MMD8P offers four options for isplaying moisture level measurements with or without the
environmental parameters (temperature an RH) that affect them.
Instea of the Full Measurement Screen above, you can choose to show moisture measurements
on an analog bar graph like the following.
To select the Analog Bar raph Screen , press the MODE button with
the Full Measurement Screen on the OLED. Note on the screen at
right that the igital rea out of moisture level has been replace by
an analog rea ing correspon ing to the wi th of the white rectangle
at left. The linear scale below the rectangle in icates values from 5.3
to 40.0%WME from left to right.
Also note the a ition of the small letters L an H at left an right,
respectively.
L in icates a measure moisture level below
5.3%WME, an
H in icates a measure moisture level above
40%WME.
Finally, note the presence of the wor
Hold in the mi le of the isplay. Hold in icates that the
currently isplaye level represents a hel measurement.
To hold a measurement , briefly press
the button. To release the hol (“unfreeze” the isplay), briefly press the button again.
Note: A hel rea ing on the Full Measurement Screen is in icate by the flashing of the
% sign
between the measure value an
WME .
The thir of the MMD8P’s four measurement isplay options is the
Large Numeric Screen shown at lower right.
To select the Large Numeric Screen , press the MODE button with
the Analog Bar Graph Screen on the OLED. On this screen, note
the absence of any in ications other than measure moisture level
an remaining battery charge. This isplay option is most useful
for rea ing moisture levels from a istance. As on the Full
Measurement Screen, hel rea ings are in icate by the flashing
of the
% sign to the right of the measure moisture value.
6
A typical Full
Measurement Screen
(Display Option 1)
A typical Analog Bar raph
Screen (Display Option 2)
A typical Large Numeric
Screen (Display Option 3)

The fourth an final measurement isplay option is the Moisture-
Hygrometer Screen, shown at right.
To select the Moisture-Hygrometer Screen, press the
MODE button
with the Large Numeric Screen on the OLED. On this screen, note
the absence of the woo species number an name an the
absence of the remaining battery charge icon. As on the Full
Measurement Screen an Large Numeric Screen, hel rea ings
are in icate by the flashing of the
% sign to the right of the
measure moisture value.
Note: When the MMD8P is powere on following a manual or
automatic (APO-triggere ) shut own, it will automatically resume
operation with the last selecte measurement isplay option.
SELECT A SPECIES
The MMD8P incorporates in ustry-stan ar moisture-resistance curves for 48 species of woo .
To select a particular species: 1) Choose either the use the Full Measurement Screen or the
Analog Bar Graph Screen (because the species number an name are not shown on the Large
Numeric Screen or Moisture-Hygrometer Screen); an 2) Use the ▲an ▼pa s of the joystick
to scroll through the species options until the number an name of the esire species appears
at the top of the screen.
The following table shows the Co e Nos. an names of each of the 48 woo species whose
moisture-resistance curves are store in the meter.
7
Fir,Douglas
Pine,Southern
SPF
Alder
Apitong
Aspen
Ash,White
Basswood
Birch
Cedar,Eastern Red
Cedar,Incense
Cherry
Cottonwood
Cypress
Elm,American
Fir,Red
Fir,White
um,Black
um,Red
Hemlock,Western
Hackberry
Hickory
Keruing
Larch
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Magnolia
Mahogany,African (also Khaya)
Mahogany,Honduras
Mahogany,Philippine
Maple,Hard/Soft
Meranti,Dark Red
Oak,Red
Oak,White
Pecan
Pine,Longleaf
Pine,Ponderosa
Pine,Shortleaf
Pine,Sugar
Pine,White
Poplar,Yellow
Ramin
Radiata Pine
Redwood
Spruce,Sitka
SPF,COFI
Teak
Virola
Walnut,Black
Western Hemlock-COFI
Species Code Chart
Code No. Wood Species Wood Species
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
Code No.
A typical Moisture-
Hygrometer Screen
(Display Option 4)

Note: Unlike in Setup mo e, pressing an hol ing the or pa of the joystick will not increase
the increment of change in Co e Nos. However, as in Setup mo e, you
can use the an 
pa s to “wrap aroun ” the low or high en of the co e range. Specifically, pressing the pa
with Co e No. 1 selecte will change the selecte co e to Co e No. 48, an pressing the pa
with Co e No. 48 selecte will change the selecte co e to Co e No. 1.
MAKING MEASUREMENTS
To measure the surface moisture level of a wood sample , first select its species using the
instructions in the previous section. Then carefully remove the cover protecting the test pins at
the top of the meter. Take care not to stab yourself with the sharp points.
Rea the moisture level on any of the four screens escribe above as Display Options
1 through 4.
General recommen s that you check the calibration of the MMD8P prior to every measurement
session. To check the calibration: 1) Select the Douglas Fir Species (Co e No. 1); 2) Make sure
that the Compensation Temperature is set to the efault value of 70°F (see page 9); 3) Remove
the pin cover, turn it over an insert the test pins into the holes on the top of the cap. A rea ing of
15.9% ±3%WME in icates a properly calibrate meter.
STORING RECORDS
If you enable the meter’s memory as part of the A vance Setup proce ure, you can store an
recall up to 100 moisture measurement recor s. During A vance Setup, you can also choose
how much memory to allocate for recor storage. As mentione earlier, as a practical matter
there is no reason not to enable memory storage, an no reason not to select the maximum
memory capacity available—100 recor s.
Each moisture-measurement recor (see example below right) contains the following
information:
• The recor number (7 out of 100 available locations) on the top line
• The moisture level measurement itself (
MoistureRead. in the example below)
• The number an name of the woo species teste (
No. 3 SPF )
• The ambient temperature an relative humi ity at the time
of measurement (
59.9°F an 60.0%RH )
• Any temperature compensation applie (
0.0°F )
• An in ication (
Record at lower left) that the recor is available
for storage.
If you have enable memory storage, the Store Mem. Screen
shown above is a e to the sequence of screens ma e available
by pressing the
MODE button. It follows the Moisture-Hygrometer
Screen in the sequence.
There are two ifferent proce ures for storing moisture
measurement recor s, epen ing on whether you choose manual or automatic storage.
To store a record in manual mode:
1. Make a measurement an view it on any of the four isplay screens.
2. If necessary, press the
MODE button until you see the Moisture-Hygrometer Screen.
3. Press the
MODE button once to isplay the Store Mem. Screen. The terms Record an
Exit on the bottom line will both flash.
4. Assuming that you have enable manual storage, press the (
MR MC ) button—
irectly un er Record — once. This stores the recor in memory. Note that pressing
the button increments the recor number counter at the upper right of the OLED.
8
A typical moisture
measurement record,
ready for storage

5. To exit recor storage mo e an a vance to the View/Delete Mem screen, press the
MODE button— irectly un er Exit .
To store one or more records in automatic mode:
1. Make a measurement an view it on any of the four isplay screens.
2. If necessary, press the
MODE button until you see the Moisture-Hygrometer Screen.
3. Press the
MODE button once to isplay the Store Mem. Screen.
4. Assuming that you have enable automatic storage, press the (
MR MC ) button
once. Doing so begins storing complete moisture measurement recor s at the
sampling rate you selecte uring the A vance Setup proce ure. Note that the
recor number at upper right will continue to increment automatically at the selecte
sampling rate. Also note that the wor
Stop will appear at the lower left of the isplay,
irectly above the (
MR MC ) button.
5. To stop automatic recor ing, press the (
MR MC ) button again.
In manual or automatic storage mo e, when the space allocate for recor s has been use up
the Store Mem. Screen will a vise the following:
MEM. FULL!
RECALLING AND DELETING RECORDS
To recall one or more stored moisture measurement records:
1. Use the MODE button to navigate to the View/Delete Mem
Screen (see photo at right). The terms
Delete an Exit will
flash on the bottom line.
2. Use the an /or pa s to navigate to the recor of
interest. The recor number appears at the upper right of the
OLED. In the example at right, the recor isplaye is No. 1
of a total of six store (in icate by 1/6 on the isplay).
To recall additional records , use the an /or pa s. Unlike in
Setup mo e, you cannot use the or pa s to fast-forwar or
fast-rewin through recor numbers. However, as in Setup mo e,
you can use the an pa s to “wrap aroun ” the low an high
en s of the range of store recor numbers.
To delete an individual record , press the ( MR MC ) button (which is irectly below Delete on
the View/Delete Mem Screen) with the recor on-screen. The next screen will ask “Are You Sure
To Delete?”, with the options
Yes an Exit , flashing, on the bottom line.
Pressing the (
MR MC ) button to answer “Yes” takes you to another screen that asks “All
Delete?” an the options
No an Yes , flashing, on the bottom line.
Pressing the (
MR MC ) button to answer “No” eletes only the selecte recor . Note that
oing so ecrements ( ecreases by one) the number of store recor s—the number following
the slash at upper right. Deleting a single recor oes not change the number before the slash.
However, that number now represents a ifferent recor —the one you save just before the
recor that you just elete .
Pressing the
MODE button to answer “Yes” to “All Delete?” eletes all store recor s an calls up
a special View/Delete Mem Screen with: 1) no Recor No./Recor Count isplay in the upper right
corner; 2) only the term
Exit , flashing, in the lower right corner; an 3) the message File not
found!
in the mi le of the screen.
Pressing the
MODE button to Exit the View/Delete Mem Screen opens the Temperature
Compensation A justment Screen (see next section).
9
A typical moisture
measurement record
during recall

COMPENSATING FOR TEMPERATURE
The MMD8P allows you to compensate moisture measurements for the effect of ambient
temperature. This feature greatly improves the accuracy of rea ings.
To select an set the level of temperature compensation, call up the
screen shown below. To o so, press the
MODE button until you see
the View/Delete Mem Screen, an then press the
MODE once more.
The efault temperature for which all MMD8P measurements are
compensate is 70°F. Using the an pa s of the joystick, you
can change the compensation temperature to any value from
0° to 255°F ivisible by 5. In other wor s, each press of the
or pa increases or ecreases the compensation temperature
by 5°F. Typically, you a just the compensation temperature until it
matches the ambient temperature.
When you have finishe a justing the compensation temperature, press the (
MR MC ) button
(which is irectly below
Save & Exit on the above screen). To “pass through” the Temperature
Compensation Selection Screen without making a change, press the
MODE button (which is
irectly below
Exit on the above screen).
Whether you use the efault compensation temperature of 70°F or another value of your
choosing, you can rea the actual value applie on the three Display Option screens that show
ambient temperature.
To isplay the compensation temperature (
TC. ) instea of the ambient temperature ( TA. ), press
the or pa of the joystick with the Full Measurement Screen, Analog Bar Graph Screen or
Moisture-Hygrometer Screen on the OLED. Doing so will cause
TC. an its value to replace TA.
an its value.
To return to showing
TA. an its value, press the or pa again.
SPECIFICATIONS
• Moisture Measurement:
Range: 5.3 to 40%WME (Woo Moisture Equivalent)
Accuracy/Resolution: ±(3% of rea ing + 5 igits)/0.1%
• Ambient Temperature Measurement:
Range: 0° to 176°F (-18° to 80°C)
Accuracy/Resolution: ±1.8°F (1°C)/ 0.1°
• RH Measurement:
Range: 20 to 95%RH
Accuracy/Resolution: ±5% of rea ing/ 1%
• Temperature Compensation Range/Resolution: 0° to 255°F (-18° to 124°C)/ 5°F
• Display Type: Yellow OLED in 128 x 64 ot matrix format
• Display Size: 1.54 in. (39mm) iagonal
• Number of Species Moisture-Resistance Curves: 48
• Memory Capacity: 99 recor s
• Auto Memory Recor ing Sampling Rate: A justable from 1 to 99 secon s
• Auto Power Off Trigger: A justable from 1 to 99 minutes of front-panel inactivity
10
The Temperature
Compensation Selection
Screen