Wohler HF 550 User manual

The Measure of Technology
Manual
Wood Moisture Meter
Best.-Nr. 23851 –2016-08-02
Wöhler HF 550

Inhalt
2
Contents 1General Information..............................4
1.1 Operation Manual Information....................... 4
1.2 Notes............................................................. 4
1.3 Proper use..................................................... 4
1.4 Transport....................................................... 5
1.5 Information on disposal................................. 5
1.6 Manufacturer................................................. 5
2Technical Data.......................................6
2.1 Wöhler HF 550 Wood Moisture Meter........... 6
2.2 Wöhler FW 550 Moisture Scale for Bulk
Material ......................................................... 7
3Device components and connections 8
3.1 Meter............................................................. 8
3.2 Probes and Moisture Scale.......................... 9
4Operation.............................................10
4.1 Switching the meter on and off.................... 10
5Check battery status and charge
battery ..................................................12
6Measuring the wood moisture of logs..
..............................................................13
6.1 Theoretical background............................... 13
6.2 Connecting the Probe.................................. 14
6.3 Measuring ................................................... 16
7Moisture Measurement of bulk material
..............................................................22
7.1 Measurement procedure............................ 22
7.2Preparation of the measurement................. 23
7.2.1 Positioning the Moisture Scale.................... 23
7.2.2 Connections ................................................ 23
7.3 Measuring ................................................... 24
8Main menu...........................................29
8.1 Moisture Measurement Delete old
measurement.............................................. 29

Inhalt
3
8.2 Selection of the material ..............................30
8.2.1 Log choice (in mode)...................................30
8.2.2 Bulk choice (when the Moisture Scale is
connected.)..................................................31
8.3 Customer.....................................................31
8.4 Save ............................................................31
8.5 Print.............................................................32
8.6 Select probe.................................................33
8.7 SETUP.........................................................33
8.8 Check HF 550 and calibration HF 550.........34
9Data administration............................35
9.1 Save records................................................35
9.2 Creating a new customer folder...................36
9.3 Customer Menu...........................................37
10 Maintenance and care........................38
11 Warranty and Service.........................39
11.1 Warranty......................................................39
11.2 Service.........................................................39
12 Accessories.........................................40
13 Sales and Service Points...................41

General Information
4
1General Information
1.1 Operation Manual In-
formation
This operation manual allows you to work safely
with the Wöhler HF 550. Please keep this manual
for your information.
The Wöhler HF 550 Wood Moisture Meter should
be employed by professionals for its intended use
only.
Liability is void for any damages caused by not
following this manual.
1.2 Notes
WARNING!
Not following this warning can cause injury or
death.
CAUTION!
Not following this note can cause permanent
damage to the meter.
NOTE!
Highlights tips and other useful information.
1.3 Proper use
When the Wöhler HF 550 Wood Moisture Meter is
connected to the Hammer Probe or the Lance
probe, it is suitable for the determination of the
moisture of firewood logs according to VDI 4206,
sheet 4 and the 1. BImSchV. (Federal Immission
Control Act)
When the Wöhler HF 550 Wood Moisture Meter is
connected to the Wöhler FW 550 Moisture Scale,
it is suitable for the determination of the moisture
of bulk material according to the requirements of
VDI 4206, sheet 4.

General Information
5
1.4 Transport
CAUTION!
Improper transport can harm the meter, scale and
probes.
Always transport the meter, scale and probes in
the provided carrying case in order to prevent
damage.
WARNING!
Always secure the sharp probe needles with the
protection cap.
1.5 Information on disposal
Electronic equipment does not belong into domes-
tic waste, but must be disposed in accordance
with the applicable statutory provisions.
You may hand in any defective batteries taken out
of the unit to recycling places of public disposal
systems or to selling points of new batteries or
storage batteries.
1.6 Manufacturer
Wöhler Technik GmbH
Schützenstr. 41
33181 Bad Wünnenberg
Tel.: [phone]
Fax: [phone]
Email: [email protected]

Technical Data
6
2Technical Data
2.1 Wöhler HF 550 Wood Moisture Meter
General technical data
Connections
Wöhler Hammer Probe, Lance Probe,
Wöhler FW 550 Moisture Scale,
Temperature Probe, USB-data transfer
Power supply
Lithium-ion battery 3.6V, 2,250 mAh, charging via USB
Working time
ca. 20 h
(depending on the operating mode and the Display Backlight)
Storage
Temperature
-20°C to +50°C
Operating
temperature
+5°C to +40 °C
Weight
255 g (without probe)
Size
59 x 38 x 200 mm
Moisture measurement of firewood logs
Display
Wood moisture u displayed in % relative to the dry mass of fuel;
user can switch to water content w displayed in % relative to the
moist mass of fuel
Wood species
14 wood species to choose from
Temperature
compensation
Measures temperature of material by means of a temperature
probe
Measurement
principle
Electrical resistance measurement
Range
Moisture: 10.0 % u - 40.0 % u, resolution 0.1 % u
Water content: 9.0 % w - 29.0 % w, resolution 0.1 % w
Accuracy
± 40 % of reading according to VDI 4206 page 4

Technical Data
7
2.2 Wöhler FW 550 Moisture Scale for Bulk Material
Moisture Measurement of bulk material
Display
Wood moisture u displayed in % relative to the dry mass of fuel;
user can switch to water content w displayed in % relative to the
moist mass of fuel
The readings are displayed on the HF 550 screen or on the PC
screen
Bulk material
Selectable: wood chips and pellets, as well as six species of grain
Measurement
principle
Dielectric mass measurement
Range
Moisture: 0.1 % u to 70.0 % u, resolution 0.1 % u
Water content: 0.1 % w to 41.0 % w, resolution 0.1 % w
Accuracy
0.1 % u to 5.0 % u, if 2 % u
±40 % of reading in the range 5,0 % u to 70,0 % u
For fuels tested according to the requirements of VDI 4206 Part 4

Device components and connections
8
3Device components and connections
3.1 Meter
Fig. 1: Device components
1. Connection for temperature probe
2. Screen
3. Keypad
4. Infrared port for the data transfer to the
Wöhler TD 100 Thermoprinter
5. Jack connection:
a) Hammer Probe
b) Lance Probe
6. USB port
a) for Charger
b) for Wöhler FW 550 Moisture Scale
7. Transport lock for activating the accu.
Fig. 2: Keypad
1. ESC-key (context-sensitive):
a) cancel the current function
b) go to the main menu
c) return to the measurement menu
2. Arrow-keys:
scroll up and down
3. ON-/Off-key (context sensitive):
a) Switch the meter on and off
(press and hold for 3 seconds)
b) Confirm
c) Save value or delete saved value
1
2
3
4
5
6
7
1
2
3

Device components and connections
9
3.2 Probes
and Moisture Scale
CAUTION!
The meter may only be used with the following
Wöhler original accessories:
Firewood logs and bulk material
Fig. 3:
Temperature probe Wöhler HF 550
The Temperature probe has to be connected to
the meter for measuring the temperature of the
sample.
Firewood log
Fig. 4: Lance Probe
The Wöhler Hammer Probe or the Lance Probe
have to be connected to meter for measuring the
wood moisture of logs.

Operation
10
Fig. 5: Wöhler Hammer Probe
The result of the resistance measurement will be
more exact, if the Hammer Probe is used, be-
cause the needles of the probe can be inserted
more deeply into the wood, so that humidity can
even be measured inside the wood.
Bulk material
Fig. 6: Wöhler FW 550 Moisture
Scale for Bulk Material
The Wöhler FW 550 Moisture Scale has to be
connected to the meter for measuring the mois-
ture of bulk material.
NOTE!
The meter will automatically detect, if a hammer/lance probe for the measurement of
firewood logs or the moisture scale is connected. The measurement mode for firewood
logs or for bulk material will automatically be displayed in this case.
4Operation
Fig. 7: Transport lock on the right side of
the meter
CAUTION!
For the transport deactivate the battery with the
transport lock. When the instrument is delivered,
the battery is always deactivated.
Push the transport lock to the left to activate
the battery. Use a pointed object (wire or pen)
for this purpose.
4.1 Switching the meter on and off
Fig. 8: Key pad with on/off-key marked
Turning on the Meter: Press on/off-key shortly
(on the right)
Turning off the meter: Long press the on/off-
key for 3 sec.
Transport lock

Operation
11
Fig. 9: Initial screen
After the meter has been switched on, a self test
ist carried out for 5 seconds.
During the self test the user has the possibility to
enter the customer menu or the diagnosis menu.
The diagnosis menu shows information about the
firmware, the version of the measurement module,
the serial number of the meter, the calibration
date, the production date and the identification
number of the meter (MIN).
For information about the customer menu, see
chapter 9.2.
After the self test , the measurement screen ap-
pears. If the Moisture Scale FW 550 is not con-
nected, the measurement mode “firewood logs”
will appear automatically on the screen. If the
Moisture Scale FW 550 is connected, the meas-
urement screen “bulk material” will appear auto-
matically on the screen.
NOTE!
Only if the Moisture Scale FW 550 is connected to
the meter before the meter is switched on , the
measurement mode “bulk material“ will appear on
screen.
For changing the measurement mode, go to
the main menu and select „Select probe”, see
chapter 8.6.

Check battery status and charge battery
12
5Check battery sta-
tus and charge
battery
Fig. 10: Battery status
When the device is switched on, the battery status
will be displayed in the upper right hand corner of
the screen. A fully charged battery is shown as a
solid green battery symbol. An empty symbol indi-
cates a discharged battery. When the battery is
almost discharged, only a red line will appear in
the battery icon. In this case, finish the measure-
ment as soon as possible.
NOTE!
It is not possible to remove the battery from the
meter.
Fig. 11: Bottom of the meter with USB-
port (marked with an arrow)
Plug the USB connector of the recharger into
the USB port at the bottom of the meter.
During the charging process a connector symbol
will appear in the battery icon.
NOTE!
Recharging empty batteries can take up to 4
hours.
WARNING!
Risk of electrical shock!
Never touch a mains plug with wet hands!
Do not expose the power pack to moisture!
Never pull the cable to remove the power pack
from the socket outlet - it could rip out the cable!
Operate the power pack only when the mains
power supply is the same as the voltage stated on
the rating plate!

Measuring the wood moisture of logs
13
6Measuring the wood moisture of logs
The Wöhler HF 550 can measure the wood moisture of logs according to VDI 4206,
part 4. This measurement is based on a resistance measurement. In order to obtain an
exact measurement, the respective material is considered.
The wood moisture depends on the temperature of the material. For this reason, the
wood temperature must be measured at first. The meter will automatically perform a
temperature compensation afterwars.
NOTE!
For measuring the wood moisture of logs the Hammer Probe or the Lance Probe must
be connected to the meter.
6.1 Theoretical background
The resistance measurement uses the needles of the Hammer Probe or the Lance
Probe. The meter will automatically determine the wood moisture u. This is the water
mass mwbound in the fuel and related to the absolute dry fuel mass mBaccording to
equation (1):
  


  
Equation 1
Explanation:
u= wood moisture
mw= water mass bound in the wood
mb= absolute dry fuel mass
NOTE!
According to the above equation the wood moisture may be higher than 100 %.

Measuring the wood moisture of logs
14
The wood moisture must not be confused with the water content. The water content is
the water mass related to the total mass of fuel and water (wet basis).
  

   
  
Equation 2
Explanation:
w = water content
mw= water mass bound to wood
mB= absolute dry fuel mass
The wood moisture can be converted to the water content as follows:
  

     
Equation 3
Explanation:
w= water content
u = wood moisture
6.2 Connecting the Probe
For the determination of the wood moisture it is necessary to connect two probes to the
meter :
1. Temperature probe, connection at the top of the meter, see figure 1, part 1
2. Wood Moisture Probe (Hammer Probe or Lance Probe), connection at the bot-
tom of the meter, see figure 1, part 5
CAUTION!
Before the meter is used, a visual check of the meter and the probes must ensure that
all functions work properly.
Before start measuring, check that the needles/electrodes of the Hammer Probe or
Lance Probe are not bent. If the electrodes are bent, the distance will not be 25 mm any
more, so that the measurement result may not be correct.

Measuring the wood moisture of logs
15
Fig. 12: Top of the meter with tempera-
ture probe connected.
Plug the Temperature probe into the corre-
spondent port at the top of the meter,
see figure 1, part 1.
NOTE!
The (+) plug is smaller than the (-) plug. Therefore
it is only possible to plug in the temperature probe
in the correct direction.
Fig. 13: Bottom of the meter with Ham-
mer Probe connected
Plug the jack of the Hammer Probe or the
Lance Probe into the correspondent plug at
the bottom of the meter, see figure 1, part 5.
NOTE!
The result of the resistance measurement will be
more exact, if the Hammer Probe is used, be-
cause the needles of the probe can be inserted
more deeply into the wood, so that humidity can
even be measured in the inside of the wood.
For using the Wöhler Hammer Probe please ob-
serve the manual of the Hammer Probe.

Measuring the wood moisture of logs
16
6.3 Measuring
Switch on the Meter, see chapter 4.1.
After the self test, the meter will automatically
switch to the measuring mode.
NOTE!
If there is no probe connected to the meter, or if
the hammer or lance probe is connected to the
meter, the measurement mode of firewood logs
will automatically appear on screen. If the Wöhler
FW 550 Moisture Scale is connected to the meter,
when the Meter is switched on, go to the main
menu, select “Select Probe” and then select “Log
probe”.

Measuring the wood moisture of logs
17
Fig. 14: Measrurement screen: Logs
Explanation
1. Selected type of wood
2. Date and time
3. Battery status
4. Actual reading of the wood moisture u
5. Actual measurement point (red)
6. Wood temperature
7. U-value: measurement point 1, already
saved
8. U-value: Measurement Point 2,
not measured yet
9. Average u-value, calculated from the
u-values that have already been saved.
10. Menu- key
11. Scroll
12. Context sensitive key to save the value ()
or to delete a value that has already been
saved (trash can icon).
1
6
7
3
9
10
12
2
11
0
4
8
5

Measuring the wood moisture of logs
18
The display is divided into a status, a menu and a
readings segment.
The type of wood is shown in the left status seg-
ment. The status window is shown in the right
status segment. It shows the time, the date and
the battery status.
The readings segment shows the measured data
and a drawing where the selected measured point
is shown in red.
The menu segment is situated at the bottom of the
display. It consists of three soft keys.
Selecting the type of wood
Fig. 15: “Log choice”menu to select the
type of wood
Press the Menu-key to bring up the main
menu.
Select “Log Choice” and confirm with OK.
The user can select between 14 types of wood,see
chapter 8.7.
With the arrow keys go to the selected type of
wood and confirm with OK.
Press the “Escape”-key to exit the “Log
choice”-menu.
Press the “Escape”-key again, to bring up the
measurement menu.

Measuring the wood moisture of logs
19
Measuring
Fig. 16: Driving in the Hammer Probe
Split the wood log in the middle and perform
the measurement immediately at the inside
part of the log.
Drive the electrodes of the Lance Probe or the
Hammer Probe into the material.
NOTE!
Measurements are to be performed diagonally to
the direction of the fibres; in other words, a line
drawn between the measurement needles would
dissect the fibre of the wood.
Average value
Fig. 17: Situation of the measurement
points at the log
In general the wood moisture should be measured
at three different points (see adjacent figure). The
meter will automatically calculate the average of
the three measurements. For a precise calculation
of the result, this triple measurement has to be
repeated three times. Therefore the meter pro-
poses 9 measurement points in total.
Please note the following points
when performing the measure-
ment:
NOTE!
Chose a measuring point without any knobs, resin
or fissures.
Do not measure at the front side or at the
exterior side of the split log.
NOTE!
The wood to be measured should have a temper-
ature of 0°C to 30 °C.
Temperature Measurement
The Wöhler HF 550 will automatically perform a
temperature compensation when measuring the
wood moisture. Therefore it is necessary to
measure the temperature before measuring the
wood moisture.

Measuring the wood moisture of logs
20
Fig. 18: Temperature Measurement
screen
NOTE!
We recommend to measure the wood tempera-
ture at the stock location of the wood.
With the arrow keys scroll to the temperature
line Twood, see adjacent figure.
Drive the needle of the temperature probe into
the log.
Wait some seconds until the temperature
value is stable.
Confirm by pressing -key.
NOTE!
You have the possibility to delete a temperature
value that has already been saved by pressing the
right key (trash icon) and to measure it again.
If you do not have a temperature probe, it is pos-
sible to enter the temperature value manually:
With the arrow keys scroll to the temperature
line Twood, see adjacent figure.
With the right arrow key select the tempera-
ture value and change it with the up and down
arrow keys.
Measurement 1
Fig. 19: The wood moisture value of the
Measurement Point 1 has been saved.
With the up- and down arrow keys scroll to the
first measurement point UMP1.
At the first measurement point, drive the nee-
dles of the moisture probe (hammer probe or
lance probe) into the wood.
The screen shows a drawing of a log with the cur-
rent measurement point marked in red.
The current reading of the wood moisture u will be
shown on screen above the drawing of the wood
Press -key to save the reading of the first
measurement.
NOTE!
You have the possibility to delete a value that has
already been saved by pressing the right key (trash
icon) and to measure it again. The trash icon will
only appear, if you select the correspondent line.