Observator Instruments DIFF User manual

OBSERVATOR
instruments
DIFF
Automatic volume flow meter
with pressure compensation
User manual
Version 11.2 - EN
TDC 16 July 2012

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Index
1. INTRODUCTION ......................................................................................................................... 4
2. DESCRIPTION AND USAGE ..................................................................................................... 5
2.1 OPERATION COMFORT AND ERGONOMICS...................................................................................6
2.2 OPERATION ..............................................................................................................................6
2.3 BEFORE FIRST USE ...................................................................................................................6
2.3.1 Inserting the batteries .....................................................................................................6
2.3.2 MEASURING POSITIONS ..........................................................................................................7
2.3.3 Operation ........................................................................................................................7
3. THE MENU .................................................................................................................................. 8
3.1 CALIBRATION ............................................................................................................................8
3.2 MEASUREMENT.........................................................................................................................9
3.3 STORAGE .................................................................................................................................9
3.4 SETTINGS...............................................................................................................................10
3.4.1 Brightness/contrast.......................................................................................................10
3.4.2 Battery...........................................................................................................................10
3.4.3 Language......................................................................................................................10
3.4.4 Measuring unit / temperature unit.................................................................................11
3.4.6 Technical menu.............................................................................................................11
3.5 OVERRANGE PROTECTION .......................................................................................................11
3.6 OFF.......................................................................................................................................11
4. EXTENSION HOODS................................................................................................................ 12
5. BATTERIES .............................................................................................................................. 13
5.1 FIRST USE OF THE BATTERIES ..................................................................................................13
5.2 COMPATIBLE BATTERIES..........................................................................................................13
5.3 BATTERY LIFE .........................................................................................................................13
5.4 LIFETIME ................................................................................................................................13
5.5 WARNINGS .............................................................................................................................13
6. MAINTENANCE ........................................................................................................................ 14
7. DIFFINER .................................................................................................................................. 15
7.1 DOWNLOADING DIFFINER .......................................................................................................15
7.2 ADDING A PROJECT .................................................................................................................16
7.3 THE DIFF WITH AN SD-CARD ..................................................................................................17
7.4 OPENING THE DATA ON THE COMPUTER....................................................................................19
7.5 SD-CARD MESSAGES ..............................................................................................................20
8 DECOMMISSIONING................................................................................................................. 21
8 DECOMMISSIONING................................................................................................................. 21
8.1 DECOMMISSIONING THE DIFF (TEMPORARY) ............................................................................21
8.2 DISPOSAL OF THE DIFF ..........................................................................................................21
9. TROUBLE SHOOTING ............................................................................................................. 22
9.1 ERRORS .................................................................................................................................22
9.2 REPLACING THE FUSE .............................................................................................................23
9.3 DIFF SPARE PARTS.................................................................................................................23
10. WARRANTY............................................................................................................................ 24
APPENDIX: DECLARATION OF CONFORMITY ........................................................................ 25

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1. Introduction
The DIFF is a tool developed by Observator for
measuring air flow and air temperature. The DIFF
is commonly used by installers and controllers in
the housing and utility industry. The DIFF can
perform a pressure compensated measurement as
specified in the building regulations in the NEN
1087, NEN 8087. The flow meter is also
recommended at the ISSO publications -61, -62, -
63 and -8010 and BRL 6000-10. Operating errors
are prevented by an automated measurement
process. The flow reading is digital and clear, this
prevents reading errors. The DIFF is prepared for data storage with SD card and the use of
DIFFiner. Please contact your dealer or Observator for this option.
The standard package contains:
DIFF automatic volume flow meter with pressure compensation
Battery charger
4 x 1,5V AA NIMH batteries
Manual
Calibration report
transport case
Optionals:
- Upgrade for data storage including PC software (DIFFiner) and 2GB SD card,
- Various attachments
- Fast charger.
Specifications
Description Value
Dimensions (250x250)x510xØ200mm
Net weight 2.9 kg with batteries without transport case.
Operating temperature -10 tot +50 ºC, 0-95% RV Not condensation
Range 10-400 m3/h, -15 tot +70 ºC
Accuracy ±3% of the reading ±1 m3/h, ±0,5ºC.
Resolution display 0,1<100>1 m3/h, 0,1 ºC.
Resolution Zero
pressure measurer
< 0,2 Pa
Power supply 4x 1,2 V AA NiMH 2700 mAh, rechargeable.
Measuring time (nom.) < 30 sec
Material casing ABS
Measuring method In accordance with NEN1087/1088/8088
EMC In accordance with EN60132-1, IEC61000-5-
5 etc
IP20 accordance IEC-60529
Battery life 8 hour while measuring 75m
3
/h

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2. Description and usage
Nr. Description
1 Scroll button
2 Information display
3 Measuring side DIFF
4 Air inlet/exhaust
5 Point of pressure measuring
6 Connection temperature sensor/motor

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2.1 Operation comfort and ergonomics
The DIFF is self adjusting for inlet and exhaust grilles. The DIFF automatically detects the flow
direction, so the DIFF does not need to be turned around. Always place the square side over or
tight against the grill. For your convenience you are able to set the arms of the Diff in any positon
that will make it is easy to operate and to read out. Just make sure the readout panel is not in the
airflow. Use of a ladder is mostly unnecessary because of these possibilities
2.2 Operation
Measuring on a vent will cause a difference in pressure caused by the measuring instrument
itself.This difference in pressure will cause a deviation in the air distribution that causes a faulty
measurement. The DIFF solves this problem by adjusting the speed of the build-in fan according
to the measurements. This makes the volume flow through the grill exactly the same as it was
before the DIFF was in place. The DIFF give the right measurement of air flow after the beep.
2.3 Before first use
Make sure there is no packing material or any other object in the DIFF.
2.3.1 Inserting the batteries
Charge the SANYO batteries as described in the manual that is included with the charger (we
recommend to read the manual carefully). The included battery charger is designed for the usage
with the SANYO AA NiMH 2700 mAh batteries. This battery charger protects the batteries against
overcharging and high temperatures. Use the standard charge mode whenever possible, but
definitely the first couple of times. The batteries are fully charged when the green LED lights
continuously lit. The batteries will only reach their full capacity after fully charging them multiple
times (see chapter 5).
Switch off the instrument when replacing the batteries. The batteries are
placed in the battery compartment on the backside of the electronics
housing. Unscrew the thumb screw to open the cover of the battery
compartment to take out the battery holder to replace the batteries.
Note the polarity when placing batteries! The electronics are protected by means of a fuse,
see item 9.2. The battery positions are marked on the black battery holder. The stud is the
+ and the flat side is the – of the batteries.
Hold the wires above the batteries when placing the batteries. The wires can be pinched off when
they are positioned below the battery holder. Push the battery holder to the right side of the
compartment and place the cover.

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2.3.2 Measuring positions
It is possible to adjust the arms by pushing both grey buttons at the same time. The arms will
“click” every 30˚. This makes it possible to set a comfortable position for every situation. The
electronics unit can be rotated to ensure a reading during the measurement.
Make sure that the display of the DIFF is not placed in front of the opening. Putting the
display in front of the air exhaust will cause faulty measurements.
These pictures show the right position of the arms and the display.
2.3.3 Operation
The DIFF can be operated with only one button. The readings are shown on the display.
The DIFF can be switched on by pushing in the middle of the scroll button. The recess in the
scroll button is intended for scrolling.

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3. The menu
The following menu will appear when the DIFF is powered.
You can scroll true the menu by rotating the control button. Push in the middle of the control
button to select the option.
3.1 Calibration
Calibration of the DIFF is necessary after powering. The ultrasensitive pressure sensor will be
adjusted to the environmental temperature.
It is advisable to let the DIFF acclimatize for a minimum of 15 minutes when there are
big differences in temperature. The DIFF has to be calibrated after the acclimatizing. It is
recommended to calibrate the DIFF from time to time during usage.
We recommend calibration of the DIFF every half an hour to secure the measuring accuracy.
It is necessary to calibrate the DIFF more often when the environmental temperature is changing
rapidly or when the DIFF has a temperature divergent from the environment.
Please note that the DIFF has to stand on a flat surface and the room has to be free of air flow.
When the DIFF is being calibrated the following screens will show up.
or
The last screen indicates that the calibration failed. The failure can be caused by air flows in the
room. Make sure that the DIFF is calibrated on a flat surface. You can put a flat object on top of
the DIFF to avoid airflow true the DIFF.
Menu
=======================
Measurement
Storage
Calibration
Off
Settings
Calibration
=======================
Calibrating…
Calibration
=======================
Testing…
Calibration
=======================
Successful.
Calibration
=======================
failed!

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3.2 Measurement
The DIFF starts to measure immediately once the option is selected from the menu. Make sure
that the following is prepared before measuring:
Close doors and windows, the wind can create pressure waves that influence the measurement.
Put the square opening of the DIFF against the vent. When sure that the vent is fully
covered the measurement can be started. The measurements can be faulty when the
measurement is started before the DIFF is in place.
The DIFF will start with a pre-measurement. You can hear the motor starts running. The
pre-measurement will be followed by the final measurement.
Wait until the measurement is completed. The measurement can take tens of seconds.
The display will show the instantaneous flow and temperature value. This value is not
reliable because the DIFF is still compensating the measurement.
There will sound a beep when the measurement is finished. The value shown on the
display is the measured value. You can remove the DIFF from the vent.
The plus sign indicates that an air inlet is being measured. It is also indicated on the upper left of
the display.
A negative sign indicates that an air exhaust is being measured. It is also indicated on the upper
left of the display.
The battery status is indicated by the blocks on the upper right of the display. It is recommended
to charge and/or replace the batteries when the battery status reaches the value of one block.
The air temperature of the air flowing through the DIFF is shown below the battery indication.
You can return to the menu by pressing the selection button. The measured value won’t be
available anymore.
Comments:
The motor can reach a RPM of thousands of rounds per minute. This can create a high pitched
tone which is normal.
Measurement duration:
The duration depends on the amount of airflow going through the DIFF. The DIFF will measure
faster when the airflow is higher.
3.3 Storage
The storage function is available as an option. We refer to chapter 7 for more information.
Supply ■■■■
Airtemp 24.5˚C
Airflow [M3/H]
+47.6

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3.4 Settings
You can choose the following options in the settings
menu:
Brightness
Contrast
Battery
Language
Measuring unit
Temperature unit
Technical Menu
3.4.1 Brightness/contrast
The following screens are shown when selecting the option brightness or contrast.
The screen gives information about the serial number and the driver number of the DIFF. The
brightness or contrast is adjustable by turning the selection button. The setting can be confirmed
by pressing the selection button.
3.4.2 Battery
The option Battery shows the percentage of battery
capacity that is left. It is possible that the percentage
goes up after a measurement.
The battery status is also shown on the display while
measuring. It is indicated with 4 white blocks in the
upper right of the screen.
It is recommended to charge and/or exchange the
batteries when the battery level has dropped to one block.
3.4.3 Language
The screen changes to an other language by turning the selection button. You can confirm the
selection by pressing the selection button.
Settings
=======================
Brightness
Contrast
Battery
Language
Meas. unit
=======================
Brightness
Driver 3.0.007
DIFF – 00220
=======================
Contrast
Driver 3.0.007
DIFF – 00220
Battery
=======================
76％
Taal
============
Nederlands
Language
============
English
Sprache
============
Deutsch

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3.4.4 Measuring unit / temperature unit
The measuring unit can be selected by turning the selection button. The setting has to be
confirmed by pressing the selection button. The following measuring units can be selected:
measuring unit:
M3/H
CFM
L/S
Temp. unit:
Celsius
Fahrenheit
3.4.6 Technical menu
The technical menu is only available by the Observator technicians.
3.5 Overrange protection
The measuring range goes up to 400m3/h. When you
try to measure a value higher then 400m3/h the DIFF
will show the screen shown on the right.
3.6 OFF
The option will power the DIFF down. The DIFF will also be turned off when it is not used for 10
minutes or more. This will prevent unnecessary energy consumption.
Meas. unit
=======================
M3/H
Temp. unit
=======================
Celsius
Overranged
=======================

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4. Extension Hoods
There are different types of hoods available for vents larger then the
standard opening of 25x25cm. The cross needs to be mounted
(Velcro) when measuring a diffuser of 40x40 or 60x60cm. The cross
avoids that the measurements are influenced by the vortices created
by the diffuser.
To mount the hood, place the round opening of the hood over the
square opening of the DIFF. The pull strings need to be positioned on
the left
.
Pull the lower pull string and lift the
hood till the lower pull string hooks
behind the sally edge of the DIFF. With
the lower pull string tightened you can
pull the upper pull string.
Note that the upper pull string needs to
be placed above the sally edge.
Span the hood by placing the fiber poles as a cross. The poles can
be placed in the recesses from the edge inside the DIFF. The fiber
poles may bend about ± 6cm while placing them.
There is also a repair kit included to repair holes in the canvas.
Check if the pull strings are fit well around the DIFF and pull them
tight if they are still a bit loose.
The AT-242 is required for measuring supply vents in the
housing industry.
The light hood simply slides over the top of the Diff and doesn’t
require any additional tightening.

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5. Batteries
5.1 First use of the batteries
Fully charge the batteries the first time in standard charging mode. The batteries will only reach
full capacity after charging them fully a couple times. The batteries are fully charged when the
green indication LEDs are continuously lit. Use fast charge will reduce the battery life, we advise
to use the standard charge mode whenever possible. For more detailed information we refer to
the charger manual.
5.2 Compatible batteries
The DIFF is designed for the usage of SANYO rechargeable NiMH batteries with a minimum
capacity of 2700mAh. Beware: Different suppliers have different specifications. The included
SANYO batteries are tested by Observator for the usage with the DIFF. We recommend to use
these batteries only!
Nonchargeable batteries, like the alkaline type, are not suitable for the DIFF. Same counts for
rechargeable batteries with less capacity. If you do use these types of batteries, keep in mind that
the range most likely will be limited to 100 - 300 m3 / h. It is also possible that the DIFF will power
itself down due of voltage drop. Nonchargeable batteries have much lower capacity then the
included batteries.
5.3 Battery life
With the DIFF fully charged you will be able to measure 1 working day (typical 8 hours of usage
when the average measuring is 75 m3/h). The actual operation time will depend on the measured
flow. When the maximum measured flow is 100 m3/h or lower, you will be able to measure upto 2
or 3 days before the batteries need to be replaced.
Tips for optimal use of the batteries:
Cold batteries can deliver less energy. Store the batteries preferably in a room with an ambient
temperature above 5°C. Take care that the batteries have the same temperature as the DIFF, this
will avoid moisture.
5.4 Lifetime
The expected lifetime of the included NiMH batteries is about 1 year when using them daily. It is
safe to assume that the batteries need replacement when they need to be charged more
frequently then before. We recommend replacing the batteries every year or when they are
charged / discharged 250 times.
Fast charging cycles will decrease the life of batteries.
Waste batteries must be disposed in accordance with the currently applicable local laws.
5.5 Warnings
Read the manual of the battery charger before using. Never try to charge nonchargeable
batteries. Only use the (included) SANYO NiMH (model HR-3U 1.2V) batteries with a minimum
capacity of 2700 mAh.
Only charge the batteries in an ambient temperature of 0…50°C in the standard battery charger.
The fast battery charger can only be used in an ambient temperature of 10….40°C. Also refer to
the manual of the battery charger.
It’s not possible to use a fixed power supply, usuage of a fixed power supply can cause
EMC problems, will void your warranty and CE approval.
Faults and damage caused by other type of batteries then specified, is excluded from
the Observator warranty. Batteries are excluded from the standard warranty terms.

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6. Maintenance
The DIFF is a precision-instrument. Simple routine checks will ensure that the DIFF will function
for many years.
Remove moisture with a clean moisture absorbent cloth before storing the DIFF.
Remove the batteries when the DIFF isn’t used for a long time.
Store and transport the DIFF always in the included transport case.
Store the DIFF in dry conditions.
Let the DIFF adjust to the ambient temperature. The DIFF will adjust faster when it is hold
against an exhaust vent.
Never remove the grills inside the DIFF.
Check the DIFF periodical for cracks.
Do not expose the DIFF to water
Do not use aggressive detergents. This will damage the DIFF.
Do not expose the hoods to sharp objects. A damaged hood can give wrong
measurements.
Observator recommends yearly calibration of the DIFF. Contact our service department
([email protected]) for the calibration.

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7. DIFFiner
DIFFiner is available as an option with the DIFF. This program makes it possible to:
Store data on a SD-card and/or a PC
Creating measuring reports
Pre-configuring of measuring points.
The DIFF is expandable with DIFFiner after purchase. The software package requires a pc with
Windows XP, Vista or Windows 7 with a minimum resolution of 1024X768.
7.1 Downloading DIFFiner
Download DIFFiner from the website
http://www.observator.com/instruments/air-
technology/support.
You can install DIFFiner with the standard settings.
Put the supplied SD-card in the card reader.
Start DIFFiner and select the SD-card in the
selection menu.
- DIFFiner needs to run as administrator when using Windows 7 (Right click on the icon
and select run as administrator)
- When the SD-card is not found you should check if the SD-card is formatted as
FAT32. Make sure that the SD-card is always formatted as FAT32
(My Computer Right click on the SD-card Format)
It is possible that the following message shows up when an external card reader (that can read
multiple types of flash cards) is used.
Click on Cancel and select the SD-card in the following window. DIFFiner will operate normally.

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7.2 Adding a project
The first time a SD-card is used you
will be asked if the SD-card needs to
be prepared for use with DIFFiner.
Click OK. The SD-card will be
prepared for DIFFiner and the
projects that are already on your hard
disk will also be copied to the SD-
card.
DIFFiner will boot when the SD-card
is ready.
Click open to create a new project
The screen that opens will show the
already existing projects. Click new to
create a new project.
It is also possible to export projects to
a DIFF file. These files can be send
to engineers on location. The engineer
can import these files onto the DIFF.
Click on new to create a new project.
It is possible to create a database in the newly appeared screen. It is
possible to ad the following items to the database:
Fan setting (position of the HRS switch)
Type of room (e.g. Living room, bedroom)
Grill position (e.g. position 1, position 2, 2mm)
Grill type (e.g. STHXX)
Grill situations (e.g. Clean, unreachable)
The created items can be used in the section
Building. You can fill in as much as possible
information of the building that is going to be
measured.

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Click open to add a building to the project.
You can add a new building or open an already existing building in the window that opens. Click
new to add a room to the building. The
following parameters are available per
room:
Room type
Number of rooms
Amount of air inlets
Amount of air exhausts
The default type of grill
The picture on the right shows what it
looks like when several rooms are
added.
Click save to save the project to the SD-
card.
It is recommended to use the standard type of SD-card(Sandisk ultra II 2.0GB or an
other class 4 SD-card) The time to store the project can increase significantly when a
different type of SD-card is used.
7.3 The DIFF with an SD-card
Put the SD-card into the DIFF and switch it on.
Go to the storage option.
In the next window you will see a list with the stored projects.
Select the project that you are going to measure
Select the building that you are going measure
Select the room
Select the grill
Menu
=======================
Measurement
Storage
Calibration
Off
Settings
Select project
=======================
Project
Project 2
Project
=======================
Building_1
Building_2
Building_3
Building_1
=======================
Living room
Toilet
Study room
Bath room
Bedroom Living room
=======================
Supply 1
Supply 2
Exhaust 1
Exhaust 2

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This screen shows the grill information that can be adjusted if
needed. It is also possible to calibrate the DIFF from this
screen. The measurement data will be stored after the
selection button is pressed. Don’t switch of the DIFF before
the data is saved.
Declaration of symbols:
≈≈DDesign flow
≈≈MMeasured flow
■■SGrill situation
■■TGrill type
■■PGrill position
After you measured all the rooms you can final check the
measurement in the resultant window. You can select this
menu option in the list with the rooms. This menu shows an
overview of the total flow measurement. The design flow is
shown as a comparison.
Supply 1
=======================
Measurement
Calibration
≈≈D : +53.7
≈≈M : +40.4
■■S : Good
Resultant
=======================
+ ≈≈D : +53.7
- ≈≈D : -53.7
= ≈≈D : +0.0
+ ≈≈M : +40.4
- ≈≈M : -35.4
= ≈≈M : +5.0

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7.4 Opening the data on the computer
With the measurements finished you can check the data on the pc.
Put the SD-card in the reader and start DIFFiner
Open the project.
The project data is now available on the pc.
The measured data can be plotted into a report by clicking print. It is also possible to export a
report to Microsoft Excel. This button is next to the print button.
The pictures below show examples of possible reports.

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The header of the report can be customized to the
style of the company. To change the header you
should place a picture called diffheader.jpg in the
DIFFiner folder. The header will now change into
the picture called diffheader.jpg. The folder
DIFFiner can normally been found in C:\Program
Files\Observator\DIFFiner or on the SD-card. It is
recommended to keep the same resolution as the
default header (800 x 120) to avoid lay-out
changes.
7.5 SD-card messages
The error SD failure can occur if the SD-card is removed
while the storage menu is opened (which is strongly
discouraged!). The DIFF will return to the main menu. If the
message occurs when the SD card is still present it may be
possible that the SD card is not inserted correctly. Please re-
insert the SD-card.
If the SD-card is removed during the writing of data an error
“SD failure 300” will occur. The number at the right will
count down. It is possible to reinsert the SD-card while the
counter is still active. The data will still be saved. Not
reinserting the SD-card will result in data loss.
If the DIFF contains corrupt data (caused by removing the
SD-card) it will show the warning “corrupt data”. The warning
disappears when you turn the selection button.
The rooms that are not corrupt can still be measured.
Put the SD-card back in the computer to restore the file
system. The SD-card will now automatically be restored
when DIFFiner starts.
SD failure
=======================
Measurement
Storage
Calibration
Off
Settings
SD failure 300
=======================
Measurement
Storage
Calibration
Off
Settings
Corrupt data
=======================