Greisinger GMH 3810 User guide

H60.0.01.6C-11

Operating Manual

Resistive material moisture measuring

GMH 3810 as of version 1.5

with integrated measuring needles

GREISINGER electronic GmbH Hans-Sachs-Str. 26 Tel.: +49 9402 / 9383-0 http://www.greisinger.de

D-93128 Regenstauf Fax: +49 9402 / 9383-33 eMail: [e-mail]

H60.0.01.6C-11 Operating Manual GMH3810 page 2 of 14

CONTENTS

1 IN GENERAL.............................................................................................................................................................................2

1.1 S

1.2 O

1.3 D

1.4 D

1.5 P

AFETY INSTRUCTIONS .........................................................................................................................................................2

PERATING AND MAINTENANCE ..........................................................................................................................................3

ISPOSAL NOTICE .................................................................................................................................................................3

ISPLAY ELEMENTS ..............................................................................................................................................................3

USHBUTTONS ......................................................................................................................................................................3

2 DEVICE CONFIGURATION...................................................................................................................................................4

2.1 'S

2.2 'S

2.3 'U

2.4 'U

2.5 'ATC': A

2.6 'A

2.7 'P

ORT': LIMITATION OF THE MATERIAL SELECTION .................................................................................................................4

OR.X': SELECTABLE MATERIALS (NOT AVAILABLE IF SORT = OFF) ......................................................................................4

NIT %': SELECTION OF MOISTURE UNIT %U / %W...............................................................................................................4

NIT T': SELECTION OF TEMPERATURE UNIT °C /°F ..............................................................................................................4

UTOMATIC TEMPERATURE-COMPENSATION.............................................................................................................4

UTO-HOLD': AUTOMATICALLY FREEZING THE STEADY MEASURE VALUE ...........................................................................4

OWER.OFF': SELECTION OF POWER-OFF DELAY..................................................................................................................4

3 SOME BASICS OF PRECISION MATERIAL MOISTURE MEASURING ......................................................................4

3.1 M

3.2 S

3.3 A

3.4 A

3.5 M

3.6 M

OISTURE CONTENT U AND WET-BASIS MOISTURE CONTENT W ..........................................................................................4

PECIAL FEATURES OF THE DEVICE........................................................................................................................................5

UTO-HOLD FUNCTION.........................................................................................................................................................5

UTOMATIC TEMPERATURE-COMPENSATION ('ATC').............................................................................................................5

EASURING IN WOOD: MEASURING WITH TWO MEASURING-PIKES ....................................................................................5

EASURING OTHER MATERIALS ...........................................................................................................................................6

3.6.1 ‘Hard‘ Materials (concrete or similar):.......................................................................................................................6

3.6.2 ‘Soft‘ Materials:...........................................................................................................................................................6

3.6.3 Measuring bulk cargo, bales and other special measures ...........................................................................................6

3.7 M

EASURING OF MATERIALS, HAVING NO CHARACTERISTIC CURVES STORED.........................................................................6

4 HINTS FOR THE SPECIAL FUNCTIONS ............................................................................................................................7

4.1 M

4.2 P

OISTURE ESTIMATION ('WET' - 'MEDIUM' - 'DRY') .....................................................................................................7

RE-SELECTION OF FAVOURITE MATERIALS ('SORT') .............................................................................................................7

5 FAULT AND SYSTEM MESSAGES.......................................................................................................................................7

6 INSPECTION OF THE ACCURACY / ADJUSTMENT SERVICES ..................................................................................7

7 SPECIFICATION ......................................................................................................................................................................8

APPENDIX A: SORTS OF WOOD .................................................................................................................................................9

APPENDIX B: ADDITIONAL MATERIALS ..............................................................................................................................14

1 In General

1.1 Safety Instructions

This device has been designed and tested in accordance to the safety regulations for electronic devices.
However, its trouble-free operation and reliability cannot be guaranteed unless the standard safety measures and special safety advises given in
this manual will be adhered to when using it.

1. Trouble-free operation and reliability of the device can only be guaranteed if it is not subjected to any other climatic conditions than those
stated under “Specification”.

2. Transporting the device from a cold to a warm environment condensation may result in a failure of the function. In such a case make sure the
device temperature has adjusted to the ambient temperature before trying a new start-up.

3. The circuitry has to be designed most carefully if the device should be connected to other devices. Internal connection in third party devices
(e.g. connection GND and earth) may result in not-permissible voltages impairing or destroying the device or another device connected.

4. Warning: Operating the device with a defective mains power supply (e.g. short circuit from mains voltage to output voltage) may result in
hazardous voltages at the device (e.g. at sensor socket)

5. Whenever there may be a risk whatsoever involved in running it, the device has to be switched off immediately and to be marked accordingly
to avoid re-starting. Operator safety may be a risk if:

- there is visible damage to the device or the device is not working as specified

- the device has been stored under unsuitable conditions for a longer time
In case of doubt, please return device to manufacturer for repair or maintenance.

6. Warning: Do not use these product as safety or emergency stop device, or in any other application where failure of the product could result in
personal injury or material damage.
Failure to comply with these instructions could result in death or serious injury and material damage.

7. Risk of injury! The used measuring heads are very sharp, use thoroughly during your measuring to eliminate a possible risk of injury.

H60.0.01.6C-11 Operating Manual GMH3810 page 3 of 14

1.2 Operating And Maintenance

• Battery
The battery has been used up and needs to be replaced, if and „bAt“ are shown in lower display. The device

!

will, however, continue operating correctly for a certain time.
the battery has been completely used up, if ´bAt´ is shown in the upper display.
The battery has to be removed, when storing device above 50°C.

Hint: We recommend removing the battery if device is not used for a longer period of time! Risk of Leakage

• Treat device and probes carefully. Use only in accordance with above specification. (do not throw, hit against etc.).

Protect plugs and sockets from soiling.

• To disconnect sensor plug do not pull at the cable but at the plug.

• When connecting the probe the plug will slide in smoothly if plug is entered correctly.

• Selection of Output-Mode: The output can be used as serial interface or as analogue output. This choice has to

be done in the configuration menu.

1.3 Disposal Notice

• Dispense exhausted batteries at destined gathering places.

• Send the device directly to us, if it should be disposed. We will dispose the device appropriate and non-polluting.

1.4 Display Elements

1 = Main Display:

2 = Auxiliary Display:

Special display elements:
3 = Moisture estimation:

4 = Warning triangle:
5 = “%u” or “%w”

Currently measured material moisture
[percent moisture content]
HLD: Measure value is ‘frozen‘ (Button 6)
Currently selected material
(or temperature when pressing Button 3)

Estimation of the material condition: via top
arrows: DRY - MEDIUM - WET
Indicates low battery
Displays unit: moisture content u or wet basis
moisture content w

All remaining arrows have no function in this version.

1.5 Pushbuttons

key 1: On/Off key
key 4: Set/Menu

press (Menu) for 2 sec.: configuration will activated

key 2, 5: During measure: select a material

p.r.t: 4.2 Pre-selection of favourite materials ('Sort')
List of selectable materials: Appendix A, Appendix B

With manual temperature compensation:

When displaying temperature (call via button 3 ‚Temp‘):
Input of temperature

up/down for configuration:

to enter values or change settings

Key 6:

Key 3: During the measure: shortly displaying temperature or changing to temperature input.

Store/↵↵↵↵:

- Measurement:
with Auto-Hold off: Hold current measuring value ('HLD' in display)
with Auto-Hold on: Start a new measure, which is ready when 'HLD' appears in the display
p.r.t. chapter 3.3 Auto-Hold Function

- Set/Menu or temperature input:
confirming of selected input, return to measure

H60.0.01.6C-11 Operating Manual GMH3810 page 4 of 14

2 Device Configuration

For configuration of the device press "Menu"-key (key 4) for 2 seconds, the first menu will be shown.
Choose between the individual values that can be set by pressing the "Menu"-key (key 4) again.
The individual values are changed by pressing the keys "5" (key 2) or "6" (key 5).
Use key "Store/↵↵↵↵" (key 6) to leave configuration and to store settings.

2.1 'Sort': limitation of the material selection

off:

Unrestricted material selection via key 2 and 5

1...8:

Material selection in-between 1 up to 8 selectable materials.

2.2 'Sor.X': selectable materials (not available if Sort = off)

Depending on the number that had been entered at ‚Sort‘ menu settings from Sor.1 up to Sor.X will be available.

Select the desired material that should be available during the measure via key 2 and 5, p.r.t: 4.2
Pre-selection of favourite materials ('Sort').

2.3 'Unit %': Selection of moisture unit %u / %w

Arrow points to “%u”

Arrow points to “%w”:

Moisture display = moisture content [%u]

Moisture display = wet-basis moisture content [%u]

2.4 'Unit t': Selection of temperature unit °C /°F

°C:

°F:

All temperature values are in degrees Celsius

All temperature values are in degrees Fahrenheit

2.5 'ATC': Automatic temperature-compensation

oFF:

on:

Atc off: Manual input of the temperature for temperature-compensation
via keys.
Atc on: temperature-compensation via temperature of the internal
temperature measuring or with an external temperature probe.

2.6 'Auto-Hold': Automatically freezing the steady measure value

oFF:

on:

Auto-HLD off: continuous measuring.
Auto-HLD on: when reaching a stable measuring result, this will be frozen

with HLD. When pressing the Store-key a new measure will be initiated.

2.7 'Power.off': Selection of Power-Off Delay

1...120:

oFF:

Hint: The settings will be set to the settings ex works, if keys ‘Set‘ and ‘Store‘ are pressed

simultaneously for more than 2 seconds.

Power-off delay in minutes.
Device will be automatically switched off as soon as this time has elapsed
if no key is pressed/no interface communication takes place
Power-off function inactive (necessary for continuous operation)

3 Some Basics Of Precision Material Moisture Measuring

3.1 Moisture Content u and Wet-Basis Moisture content w

Depending on the Application one of the two units is necessary.
Carpenters, joiners and the like commonly use the moisture content u (sometimes referred to as MC).
When evaluating firewood, wood chips etc., the wet basis moisture content w is needed.
The instrument can be configured to both of the values. Please refer to chapter “configuration“.

Moisture content u or MC (relative to dry weight) = dry basis moisture content (mind the arrow at left bottom!)

The unit is %, sometimes used: % MC.
The unit expresses the moisture content like calculated below:

Moisture content u [%] = (weight

- weight

wet

Or:

) / (weight

water

weight
weight
weight

Moisture content u [%] = (weight

: weight of the wet material

wet

: weight of water in the wet material

water

: oven-dry weight of material

dry

Example: 1kg of wet wood, which contains 500g of water has a moisture content u of 100%

) / weight

dry

) *100

dry

dry

*100

H60.0.01.6C-11 Operating Manual GMH3810 page 5 of 14

Wet-Basis Moisture Content w (relative to total weight, mind the arrow at left bottom!)

The wet-basis moisture content expresses the ratio of the mass of water to the total mass of the substance. The ratio
is represented by the following equation (the unit is % as well):

wet-basis moisture w[%] = (weight

- weight

wet

) / weight

dry

wet

*100

Or:

wet-basis moisture w[%] = (weight

) / weight

water

wet

*100

Example: 1kg of wet wood, which contains 500g of water has a moisture content u of 50%

3.2 Special features of the device

466 wood specimens and 28 building materials are stored directly in the memory of the device:

Thus more exact measurements could be reached than common devices with group selections would ever reach.
Even the use of involved conversion tables for building materials will cease to exist!
Example: Common wood-moisture-measuring-devices use one single group for spruce and oak, in reality the deviation
of these characteristic curves is more than 3%! Base for this statement are complex statistical surveys, considered
measuring range 7-25%). This random error will not occur for the whole GMH38xx series, with the help of individual
characteristic curves highest resolution is achieved.

Extreme wide measuring range: 0-100% (depending on characteristic curve) percent moisture content in wood.
Moisture estimation: Additionally to the measuring value, an individual moisture estimation will be displayed

simultaneously.

3.3 Auto-Hold Function

Particularly when measuring dry wood, electrostatic charges and other similar noise could dither the measuring value.
With activated auto-hold function the device will acquire an exact measuring value automatically. During that, the
device could be put down to avoid noise through discharge of the clothing etc. After having acquired the measuring
value, the display will change to ‘HLD’: The value will be frozen as long as a new measuring is initiated by pressing
button 6 (store).

3.4 Automatic temperature-compensation ('Atc')

An exact temperature compensation is important for a reliable wood-moisture-measuring. These devices feature a
integrated temperature measuring and a manual input of the temperature.

The used temperature value therefore is:

Menu Used temperature-value

Atc on Device-internal temperature-measuring
Atc off

Manual input of temperature: shortly press Temp-Button then use 5 (button 2) or 6 (button 5) to input the
temperature confirm selection with ‘Store‘(button 6)

Table 4.2: Using of the temperature-compensation

3.5 Measuring In Wood: Measuring With Two Measuring-Pikes

For measuring wood, punch in the measuring-pikes across to the wood-grain, having a good contact between the pikes
and the wood (measuring along wood-grain deviates minimal).

DO NOT HIT ONTO THE DEVICE OR PUNCH THE NEEDLES IN WITH FORCE!

The device may be damaged.
Select correct wood-sort (see Appendix A).
Ensure measuring the correct temperature (see chapter 3.4).
Now read the measuring-value or when having activated the auto-hold-function initiate a new measuring by pressing
Store/↵↵↵↵ (button 6) .
The measured resistance will be extremely high when measuring dry wood (<15%) thus the measuring will need more
time to achieve its terminal value among other things static discharge could momentarily falsify the measuring.
Therefore beware of static discharge and wait long enough until a stable measuring value is displayed (unstable: „%“
blinking) or use the auto-hold-function (see chapter 3.3 Auto-Hold Function).
Extreme accurate measures can be carried out within the range of 6 to 30%.
Beyond this range the acquirable accuracy will lessen, but the device will deliver reference values still sufficient for the
practitioner.
It is measured between the measuring-pikes insulated among each other. Requirements for an exact measurement:

- choose correct place to measure: place should be free of irregularities like resin–clusters, knurls, rifts, etc.

- choose correct measure depth: Recommendation: for trimmed timber: press in the pikes up to 1/3 of the material

thickness.

- Perform multiple measurements: the more measurements will be averaged, the more exact the result will be.

- Pay attention to temperature-compensation: let the device adapt to the temperature of the wood (Atc on) or enter

the exact temperature manually (Atc off).