halstrup-walcher EMA 200 User manual

Instruction Manual
EMA 200 Digital Pressure Gauge
halstrup-walcher GmbH
Stegener Straße 10
D-79199 Kirchzarten, Germany
Phone: [phone]
Fax: [phone]
E-Mail: [e-mail]
Internet: www.halstrup-walcher.com
Document 7100.004074 Version 3.207/2012

EMA 200 Instruction Manual
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Table of Contents
1Purpose of instruction manual................................................................................................3
2Conformity..............................................................................................................................3
3Safety precautions .................................................................................................................4
3.1 Appropriate use......................................................................................................................4
3.2 Troubleshooting, maintenance, repairs, disposal...................................................................4
3.3 Symbols .................................................................................................................................5
4Instrument description............................................................................................................6
4.1 Functions................................................................................................................................6
4.2 Instrument controls.................................................................................................................6
5Start-up ..................................................................................................................................7
5.1 Electrical connections ............................................................................................................7
5.2 Pneumatic connections..........................................................................................................7
6Operating the instrument........................................................................................................7
6.1 Switching the instrument on/off..............................................................................................7
6.2 Display modes: measurement, hold, max., min. ....................................................................7
6.3 Changing pressure units ........................................................................................................8
6.4 Zeroing key ............................................................................................................................8
6.5 Analogue output.....................................................................................................................9
7Configuration..........................................................................................................................9
7.1 Setting units of pressure ........................................................................................................9
7.2 Temperature display ............................................................................................................10
7.3 Flow-rate display(not available with 200kPa Range) ...........................................................10
7.4 Media density(not available with 200kPa Range) ................................................................10
7.5 Pitot factor(not available with 200kPa Range) .....................................................................11
7.6 Setting the scale for the analogue output.............................................................................11
7.7 Analog offset for +/- measurement.......................................................................................11
7.8 Attenuation...........................................................................................................................11
7.9 Auto On/Off..........................................................................................................................12
7.10 Default settings ....................................................................................................................13
8Troubleshooting ...................................................................................................................14
9Technical data......................................................................................................................15
10 Drawings..............................................................................................................................17

EMA 200 Instruction Manual
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1 Purpose of instruction manual
This instruction manual describes the features of the EMA 200 digital pressure gauge
and provides guidelines for its use.
Improper use of this instrument or failure to follow these instructions may cause injury
or equipment damage. All individuals responsible for operating this instrument must
therefore be properly trained and aware of the hazards, and must carefully follow
these operating instructions and the safety precautions detailed within. Contact the
manufacturer if you do not understand any part of this instruction manual.
Handle this manual with care:
It must be readily available throughout the lifecycle of the instrument.
It must be provided to any individuals who assume responsibility for operating the
instrument at a later date.
It must include any supplementary materials provided by the manufacturer.
The manufacturer reserves the right to continue developing this instrument model
without documenting such development in each individual case. The manufacturer
will be happy to determine whether this manual is up-to-date.
2 Conformity
This instrument corresponds to the state of the art and meets all legal requirements
set forth in EC directives as evidenced by the CE label.
© 2006
The manufacturer owns the copyright to this instruction manual. This manual contains
data, instructions and drawings pertaining to the features and usage of this
instrument; copying this manual in part or in full or distributing it to third parties is
prohibited.

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3 Safety precautions
3.1 Appropriate use
The EMA 200 is a portable, battery-powered digital pressure gauge for measuring
positive and negative differential pressures. At the heart of this precision instrument is
a pressure measurement capsule containing a membrane spring; the deflection of
this spring is then ascertained via an inductive measurement principle. Because it is
durable and easy-to-use, the EMA 200 lends itself well to maintenance work and
customer servicing for heating, air-conditioning and ventilation units, where it can be
used for monitoring filters, measuring fireplace drafts and wind pressure, etc.Its
precision and reproducibility also make the EMA 200 is highly suitable for use in
laboratory applications.
Always observe the operating requirements—particularly the permissible supply
voltage—indicated on the rating plate and in the “Technical data” section of this
manual.
The instrument may only be handled as indicated in this manual. Modifications to the
instrument are prohibited. The manufacturer is not liable for damages caused by
improper use or failure to follow these instructions. Violations of this type render all
warranty claims null and void.
3.2 Troubleshooting, maintenance, repairs, disposal
The individual responsible for the electrical connections must be notified immediately
if the instrument is damaged or if errors occur.
This individual must take the instrument out of service until the error has been
corrected and ensure that it cannot be used unintentionally.
This instrument requires no maintenance.
Only the manufacturer may perform repairs that require the housing to be opened.
The electronic components of the instrument contain materials that can be reused.
For this reason the instrument must be recycled in accordance with the environmental
guidelines of the jurisdiction in question once it has been taken permanently out of
service.

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3.3 Symbols
The symbols given below are used throughout this manual to indicate instances when
improper operation could result in the following hazards:
WARNING! This warns you of a potential hazard that could lead to bodily injury up
to and including death if the corresponding instructions are not followed.
WARNING: This warns you of a potential hazard that could lead to significant
property damage if corresponding instructions are not followed.
INFORMATION: This indicates that the corresponding information is important
for operating the instrument properly.

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4 Instrument description
4.1 Functions
The EMA 200 is a battery-operated, digital pressure gauge for measuring
overpressure, vacuum and differential pressure of non-aggressive gases. Operating
range is 200 Pa to 200 kPa.
Because it is robust, easy-to-use and includes an analogue output, this instrument is
especially suitable for maintenance, customer service and record-keeping for heating,
ventilation and air-conditioning units.
At its heart is a pressure measurement capsule with a beryllium bronze membrane
spring, which is displaced by the pressure difference between the two chambers of
the measurement capsule. Measurement range is between 200 Pa and 20 kPa. A
distance measurement system converts this displacement into an electrical signal.
A semiconductor sensor is used for measuring pressures in the area of 200 kPa.
4.2 Instrument controls
The instrument control panel consists of a keypad with four buttons.
pressure display
flow-rate / temperature display
on/off
select key: pressure, min.,
max., hold
select key: pressure units
zero-point calibration /
configuration

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5 Start-up
5.1 Electrical connections
Use only IEC 6 LR 61 batteries.
Open the battery compartment on the rear of the instrument by sliding off the
compartment cover. Plug the batteries in to the battery hook-up, making sure that the
battery terminals are properly aligned. Place the battery in the compartment and
replace the cover.
5.2 Pneumatic connections
Connect the EMA 200 to the pressure source at the overpressure port (+) when
measuring overpressure, at the vacuum port (-) for measuring vacuum pressure, or at
both ports (making certain to connect the + and - ports appropriately) for measuring
differential pressure.
6 Operating the instrument
The following sections explain how to operate the instrument correctly.
6.1 Switching the instrument on/off
Turn the instrument on or off by briefly depressing the key. The
instrument displays its measurement range in mbar for roughly 1 s
immediately after it is switched on.
6.2 Display modes: measurement, hold, max., min.
The key allows the user to toggle between the various display modes
Pressing this key once will call up a different display mode. In hold, max and
min modes, users can begin a new measurement by briefly depressing the
zeroing key. In the display modes min and max, this will reset the
display value, because the actual value will be the new min or max value.

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Display
mode
Min
arrow
Max
arrow
Display
normal
measurement
off
off
instrument displays current
pressure value
hold
on
on
instrument displays pressure
value prior to switching modes
max
off
on
instrument displays the largest
measured pressure
min
on
off
instrument displays the smallest
measured pressure
6.3 Changing pressure units
The instrument allows the user to toggle between a number of different units of
pressure. Users can change pressure units during normal operation by
depressing the key. The following units are available:
The instrument will use the new units until it is switched on/off or until the next
time the units are changed. The units selected during configuration (see
section 7) are always set when the instrument is switched on.
6.4 Zeroing key
The effects of temperature and positioning of the measurement capsule may
cause the zero-point to shift, thereby distorting the measurement result, i.e.,
causing the instrument to display a measured value even when it is not
connected to a source of pressure. Users can recalibrate the zero point by
briefly pressing the key.
It is critical that the instrument not be connected to an external source of
pressure when zeroing.
Pressure units
Factor for converting to Pa
Flow rate in
1 kPa =
1000
m/s
1 Pa =
1
m/s
1 mbar(hPa) =
100
m/s
1 mmH2O =
9,80665
m/s
1 inH2O =
249,08891
fpm x 100

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6.5 Analogue output
The EMA 200 has a 0...2V analogue output, allowing it to read out an output
voltage proportional to the pressure. When configuring the instrument, users
may set the pressure at which the instrument will read out an output voltage of
2.0V. The output voltage is read out of the instrument via a 3.5 mm jack.
For electrical connection, see following assignment:
7 Configuration
By adjusting the configuration settings, users can adapt the instrument to their
specific application. This menu can be activated by depressing the zero-point
key until 'ConF' appears in the top line of the display. After the
operator releases this key, the instrument launches the first item (setting units
of pressure). To exit the configuration menu, simply press the zero-point key
again until 'MEAS' appears in the top line of the display. The new settings are
now saved and can be used each time the instrument is switched on.
7.1 Setting units of pressure
The symbol '[P]' will appear in the bottom line of the display and one of the
pressure units will either be displayed or indicated as active by means of an
arrow. Users may now set the desired units by pressing the and
keys. Briefly depressing the key will exit this mode and the instrument
will continue on to the next configuration parameter.
shield –GND
analogue output
GND

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7.2 Temperature display
The symbol '°C' is shown in the bottom line of the display and the current
status of this switch (on or off) is shown in the top line. Users may change the
status by depressing the and keys, and may finish entering
their settings by pressing the key. The temperature display will
automatically switch off if, during the subsequent step, the flow rate display is
activated. (The instrument can only display either temperature or flow rate, but
not both.)
7.3 Flow-rate display(not available with 200kPa Range)
'SPd' (SPeed) will now appear in the bottom line of the display to indicate the
function that controls the flow-rate display. The current status of this switch (on
or off), shown in the top line, may be altered by pressing the and
keys. Briefly depressing the key will exit this mode. If the flow-rate
display has been activated, the menu for setting the density of the medium to
be measured appears; if not, the next step is to set the scale for the analogue
output (section 7.6).
7.4 Media density (not available with 200kPa Range)
This configuration parameter is represented in the bottom line of the display by
the symbol 'ro'. The top line displays the density as it is currently set and the
instrument waits for the user to enter the density of the medium to be
measured. The keypad buttons perform the following functions:
Selects which digit of the display is to be changed (digit will flash).
Increases the selected digit in increments of +1 (0...90). If the set next
value exceeds the limits of the setting range, it is not added onto the
highest digit (no overflow); the digit in question is instead set back to 0.
Exits the density entry mode and continues on to the pitot factor.

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7.5 Pitot factor(not available with 200kPa Range)
This step, represented by the 'Pit' symbol in the bottom line of the display,
allows the user to enter the factor for a pitot tube.
Selects which digit of the display is to be changed (digit will flash).
Increases the selected digit in increments of +1 (0...90). If the set
value exceeds the limits of the setting range, it is not added onto the
next highest digit (no overflow); the digit in question is instead set back
to 0.
Exits the entry mode for the pitot factor and continues on to the next
step: entering the 2V pressure for the analogue interface.
7.6 Setting the scale for the analogue output
This configuration parameter is used for setting the pressure at which the
analogue output reads out 2V. Users have the option here of setting the
analogue output to any desired final pressure between 20 and 100% of the
measurement range. While operators may enter final pressures <20%, doing
so will decrease the DA resolution. The bottom line of the display will show the
code 'AnH.'
Selects which digit of the display is to be changed (digit will flash).
Increases the selected digit in increments of +1 (0...90) If the set
value exceeds the limits of the setting range, it is not added onto the
next highest digit (no overflow); the digit in question is instead set back
to 0.
Exits this mode and continues on to the next step: entering
attenuation.
7.7 Analog offset for +/- measurement
7.8 Attenuation
It may be desirable to determine and display an average value over a specific
period if input pressures fluctuate significantly. This parameter allows the user
to set the number of measured values to be used to determine an average.
Assuming a display rate of 2 measurements per second, this value (1...20)
sets an attenuation time between 1 and 10 seconds. The bottom line of the
display will show the code 'dAn.'
Selects which digit of the display is to be changed (digit will flash).

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Increases the selected digit in increments of +1 (0...90). If the set
value exceeds the limits of the setting range, it is not added onto the
next highest digit (no overflow); the digit in question is instead set back
to 0.
Exits this mode and continues on to the next step: activating the Auto
on/off function.
7.9 Auto On/Off
The EMA 200 has an auto on/off function that can be used to avoid consuming
battery power unnecessarily. This feature (which can be toggled on and off)
will power down the instrument after 20 minutes if the pressure does not
change during this time and no buttons are pressed. The wait period is reset to
20 min. every time the user depresses a button or the pressure fluctuates. The
bottom line of the display will show the code 'Aut.'
Turns this function on or off.
Turns this function on or off.
Exits this mode and continues on to the next step: returning settings to
default values.

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7.10 Default settings
This parameter is used to reset the instrument to its default settings if desired.
The bottom line of the display will show the code 'rES.'
Turns this function on (yes) or off (no).
Turns this function on (yes) or off (no).
Exits this mode and returns to measurement mode.

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8 Troubleshooting
Error description
Potential cause
Corrective action
display does not appear
dead battery
install new battery
use a 9V IEC 6 LR 61 battery
instrument returns false
values
zero point has shifted
battery is low
adjust zero point
(see section 4.4)
'Batt' appears in the display field,
i.e., replace battery
zero-point calibration
cannot be performed
defective pressure measurement
capsule
send the instrument to the
manufacturer for repair

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9 Technical data
linearity:

0.5% of FVM at 22°C
temp.-dependent drift,
measurement range

0.04%/°C of FVM
temp.-dependent drift, offset:

0.04%/°C of FVM (for gradual changes in
temperature)
overload range 10 x FVM (for ranges

20 kPa)
2 x FVM (for ranges > 20 kPa)
response time 0.5s
display:

4-place LCD for pressure
resolution: 0.005% of FVM for 0<P<0.5
0.05% for P > 0.5 FVM
0.005% 0>P>-0.1 FVM
0.05% -0.1% FVM > P > -FVM
(FVM = final value in the meas. range)

3-place LCD for flow rate
temp.measurement:

resolution 1°C

accuracy:

1 °C

measurement range: 0 ... 60°C
analogue output: max. output voltage: 3.3V
permissible load: >=2kΩ
temperature range: storage temperature -10 ... +70°C
operating temperature range 0 ... 50°C
supply voltage:

9V IEC 6 LR 61 monoblock battery
(alkaline-Mn)

battery life, in operation: approx. 120 h

battery life, in standby mode: approx.
2000 h
pressure port: universal tubing ports
3...6 mm inner diameter
housing:

TEKNET TN22-B.29

units indicated on keypad

four buttons
operating position: preferably horizontal; positioning error may
be corrected using the "zero-point
calibration" key

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weight: approx. 300 g, including battery
miscellaneous: The automatic off function switches the instrument
off after it has been "quiet" for approx. 20 minutes.
This "quiet time" is interrupted whenever the
pressure changes by more than 2% of the final value
or the operator presses a button. Each time this
happens, the wait period is reset to 20 minutes.
Appendix A: Parts in contact with measurement medium
Beryllium bronze CuBe2 Araldite CY236 / HY988
Mu metal (nickel alloy) Loctite 242e
Brass CuZn39Pb3 Ferrit
Aluminium AlCuMgPb / AlMg3 KEL (FPM: fluorinated rubber)
Viton(tubing) Vepuran Vu 4457/51
Crastin (PTBP) UHU-Plus endfest 300 binder

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10 Drawings
analogue output
3,5 mm jack