GREISINGER GMH 5155 User manual

H82.0.03.6C-10
GHM Messtechnik GmbH • Standort Greisinger
Hans-Sachs-Str. 26 • D-93128 Regenstauf
+49 (0) 9402 / 9383-0 +49 (0) 9402 / 9383-33 [email protected]
WEEE-Reg.-Nr. DE 93889386
as of version 1.0 GMH 5155
Operating Manual
Handheld Double-Pressure-Meter
water-proof, with data logger

Please carefully read these instructions before use!

Please consider the safety instructions!

Please keep for future reference!

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Index
1GENERAL NOTE......................................................................................................................................................3
2SAFETY......................................................................................................................................................................3
2.1 INTENDED USE.......................................................................................................................................................3
2.2 SAFETY SIGNS AND SYMBOLS................................................................................................................................3
2.3 SAFETY GUIDELINES..............................................................................................................................................3
3PRODUCT SPECIFICATION..................................................................................................................................4
3.1 SCOPE OF SUPPLY ..................................................................................................................................................4
3.2 OPERATION AND MAINTENANCE ADVICE..............................................................................................................4
4HANDLING................................................................................................................................................................5
4.1 DISPLAY ELEMENTS...............................................................................................................................................5
4.2 PUSHBUTTONS.......................................................................................................................................................5
4.3 CONNECTIONS .......................................................................................................................................................6
4.4 POP-UP CLIP...........................................................................................................................................................6
5START OPERATION................................................................................................................................................7
6CONFIGURATION...................................................................................................................................................7
7REMARKS TO SPECIAL FEATURES ................................................................................................................10
7.1 DIFFERENT PRESSURE UNITS ..............................................................................................................................10
7.2 DIFFERENT KINDS OF MEASURING.......................................................................................................................11
7.3 WATER DEPTH /LEVEL MEASUREMENT...............................................................................................................11
7.4 SEA-LEVEL CORRECTION FOR ABSOLUTE PRESSURE SENSORS............................................................................11
7.5 AVERAGING FUNCTION........................................................................................................................................12
7.6 CALC: PRESSURE CHANGE PER TIME DP/DT (ONLY FOR SENSOR 1)...................................................................12
7.7 CALC: PITOT MEASURING OF VELOCITY AND FLOW (ONLY FOR SENSOR 1)......................................................13
8DATA LOGGER......................................................................................................................................................14
8.1 MANUAL RECORDING (“FUNC-STOR”) ...............................................................................................................14
8.2 AUTOMATIC RECORDING WITH SELECTABLE CYCLE TIME (“FUNC CYCL“).....................................................15
9UNIVERSAL OUTPUT...........................................................................................................................................17
9.1 INTERFACE...........................................................................................................................................................17
9.2 ANALOG OUTPUT.................................................................................................................................................18
10 INPUT ADJUSTMENT........................................................................................................................................18
11 PRESSURE CONNECTION TO THE SENSORS............................................................................................18
12 ALARM (“AL.”) ...................................................................................................................................................19
13 REAL TIME CLOCK (“CLOC”).......................................................................................................................19
14 ACCURACY CHECK / ADJUSTMENT SERVICE ........................................................................................19
15 REPLACING BATTERIES.................................................................................................................................19
16 ERROR AND SYSTEM MESSAGES................................................................................................................20
17 RESHIPMENT UND DISPOSAL.......................................................................................................................20
17.1 RESHIPMENT ....................................................................................................................................................20
17.2 DISPOSAL INSTRUCTIONS.................................................................................................................................20
18 SPECIFICATIONS...............................................................................................................................................21

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1 General Note
Read this document carefully and get used to the operation of the device before you use it. Keep this
document within easy reach near the device for consulting in case of doubt.
Mounting, start-up, operating, maintenance and removing from operation must be done by qualified, specially
trained staff that have carefully read and understood this manual before starting any work.
The manufacturer will assume no liability or warranty in case of usage for other purpose than the intended
one, ignoring this manual, operating by unqualified staff as well as unauthorized modifications to the device.
The manufacturer is not liable for any costs or damages incurred at the user or third parties because of the
usage or application of this device, in particular in case of improper use of the device, misuse or malfunction
of the connection or of the device.
The manufacturer is not liable for misprints.
2 Safety
2.1 Intended Use
This device must only be used with one or two “GMSD… - K51”or “MSD … ..E”pressure sensors.
Other usages are not intended.
The safety requirements (see below) have to be observed.
The device must be used only according to its intended purpose and under suitable conditions.
Use the device carefully and according to its technical data (do not throw it, strike it, …)
Protect the device from dirt.
2.2 Safety signs and symbols
Warnings are labeled in this document with the followings signs:
DANGER
Caution! This symbol warns of imminent danger, death, serious injuries
and significant damage to property at non-observance.

Attention! This symbol warns of possible dangers or dangerous
situations which can provoke damage to the device or environment at
non-observance.
Note! This symbol point out processes which can indirectly influence
operation or provoke unforeseen reactions at non-observance.
2.3 Safety guidelines
This device has been designed and tested in accordance with 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 the device.
1. Trouble-free operation and reliability of the device can only be guaranteed if the device is not subjected to
any other climatic conditions than those stated under "Specification".
If the device is transported from a cold to a warm environment condensation may cause 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.

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

2. If there is 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
- 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.
3. When connecting the device to other devices the connection has to be designed most thoroughly as
internal connections in third-party devices (e.g. connection GND with protective earth) may lead to
undesired voltage potentials that can lead to malfunctions or destroying of the device and the connected
devices.
This device must not be run with a defective or damaged power supply unit.
Danger to life due to electrical shock!
4. Do not use these products as safety or emergency stop devices 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.
5. This device must not be used at potentially explosive areas! The usage of this device at
potentially explosive areas increases danger of deflagration, explosion or fire due to
sparking.
3 Product Specification
3.1 Scope of supply
The scope of supply includes:
GMH 5155 with 2 AAA batteries
Operation manual
Short form manual
3.2 Operation and maintenance advice
1. Battery operation:
If ‘bAt’ is shown in the lower display the battery has been used up and needs to be replaced. However,
the device will operate correctly for a certain time. If ‘bAt’ is shown in the upper display the voltage is too
low to operate the device; the battery has been completely used up. Battery change: p.r.t. chapter 15.
The battery has to be taken out, when storing device above 50 °C.
We recommend taking out battery if device is not used for a longer period of time.
After recommissioning the real-time clock has to be set again.
2. Mains operation
The output voltage of a connected power supply unit has to be between 4.5 and 5.5 V DC.
Don’t apply overvoltage!
3. Treat device and sensor carefully. Use only in accordance with above specification. (do not throw, hit
against etc.). Protect plug and socket from soiling.
4. Connecting/changing sensors
Use only sensors of GMSD ... - K51 or MSD - series!
Other sensors may lead to damage to the device and the sensor.
Switch off device before changing the sensor.
The sensors are coupled to the instrument via bayonet connectors
To connect a sensor, plug in the connector in the right position and then rotate the ribbed ring ½ turn.
To disconnect rotate the ribbed ring ½ turn and then pull out the connector.
_DANGER
_DANGER
_DANGER
_DANGER

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4 Handling
4.1 Display elements
1
Main display: measuring value sensor 1
2
Secondary display:measuring value sensor 2 or
difference sensor 1 –sensor 2 /“CALC”
3
Arrows for selected measuring unit
4
Rating of battery status
5
Display elements to show minimum / maximum / memorized
measuring value as well as tare-function and sea-level-
correction
6
user arrow: measuring value is shown in freely adjustable
user-unit (please refer to chapter 7.1)
7
corr arrow: zero-point or slope correction is active
8
logg arrow: logger is ready
arrow flashing: automatic recording (Logg CYCL) is active
4.2 Pushbuttons
On / off key, backlight
press shortly: activate backlight or switch on instrument
press longer: switch off instrument
set / menu:
press shortly: display change:
- measuring value sensor 2
- difference sensor 1 –sensor 2
- calculated value (“CALC”, please refer
to chapter 7.6 and 0
press for 2 sec. (menu): invoke configuration menu
min / max:
press shortly: min. or max. value is displayed
press for 2 sec: the corresponding value is deleted
press shortly: tare-function: display is set to 0. All measuring
values are displayed relatively to this set tare-
value from now on.
press for 2 sec: deactivate tare-function
store / enter:
Logger off: hold and save current measuring value (‘HLD’ is
displayed)
(Logger on: Operation of data logger - chapter 8)
(Set/Menu: confirm settings, return to measuring)

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4.3 Connections
Universal output: interface, supply, analog output
(p.r.t. chapter 9 “Universal Input”)
7-pole bayonet connector: connection for sensor 2
7-pole bayonet connector: connection for sensor 1
4.4 Pop-up clip
Handling:
•Pull at label “open” in order to swing open the pop-up clip.
•Pull at label “open” again to swing open the pop-up clip further.
Pop-up clip closed
Pop-up clip at position 90°
Pop-up clip at position 180°
Function:
• The device with a closed pop-up clip can be plainly laid onto a table or attached to a belt, etc.
• The device with pop-up clip at position 90° can be set up on a table, etc.
• The device with pop-up clip at position 180° can be suspended from a screw or the magnetic holder
GMH 1300.
Device attached to a belt
Device set up on a table
Device suspended from
magnetic holder
GMH 1300

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5 Start Operation
Connect sensors, turn device on via key.
After segment test the device displays some configuration:
if standard measurement is selected
if fast measurement is selected
if peak value detection is selected
After that the device is ready for measuring.
6 Configuration
Some menu points depend on current device settings (e.g. some points are locked if logger
memory contains data sets).
To change device settings, press “menu” for 2 seconds. This will activate the configuration menu (main
display: “SEt”). Pressing “menu” changes between the menus points, pressing jumps to the
referring parameters, which can be selected with key .
The parameters can be changed with or .
Pressing “menu” again jumps back to the main configuration menu and saves the settings.
“enter” finishes the configuration and returns to standard measuring operation.
Pressing “menu” and “store” at the same time for more than 2 seconds will reset the device
to factory defaults.
If there are data sets stored and logger is set to “manual recording” (“Func Stor”) the first
menu point displayed is “rEAd Logg” (p.r.t. chapter 8 “Data Logger”)
If no key is pressed for more than 2 minutes the configuration will be aborted. All changes will
not be saved!
Menu
Parameter
Value
Description
or
Set Configuration: General configurations
Unit: Select measuring unit
*,**
Arrow to bar,
mbar …
Measuring value is displayed in corresponding unit, the selectable
units depend on connected sensor
Arrow to “user”
Measuring value is displayed in freely adjustable user-unit
bar, mbar
Unit “user”: base unit
0000, 000.0,
….0000“
Unit “user”: decimal point setting (only if user-unit selected)
-19999...19999
Unit “user”: multiplication factor
Sea Level: Sea-level correction
*,**
oFF
Sea-level correction off
on
Sea-level correction on (p.r.t. 7.4)
-2000 ... 9999
Sea-level in [m] (only available by Sensor1 SL = on)
*,**

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Menu
Parameter
Value
Description
or
Rate: Measuring rate
*
Slo
Slow measuring rate (4 Hz filtered, low power consumption)
FASt
Fast measuring rate, filtered (1000 Hz)
P.dEt
Peak detection: fast measuring rate, unfiltered (1000 Hz)
Averaging Filter
*
1 … 120
Averaging period in seconds
oFF
Averaging function is deactivated
Auto Power-Off: Select power-off delay
1 ... 120
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
oFF
Automatic power-off function deactivated (continuous operation)
Background illumination
oFF
Illumination deactivated
5 … 120
Turn off illumination after 5 … 120s (factory settings: 5 s)
on
Illumination always on
Set Calculation: Calculated display values (based on Sensor 1)
*
Choice of function
oFF
No calculated display
dP:dt
Pressure change per time (leak rate measurements, ...)
SPEd
Flow speed measurement with pitot tube etc.
FLo
Volumetric flow rate measurement with pitot tube etc.
“dP:dt”: Settings
Time unit of pressure change rate
Per.S
Pressure change rate unit per second, e.g. mbar/s
Per.n
Pressure change rate unit per minute, e.g. mbar/min
Per.h
Pressure change rate unit per hour, e.g. mbar/h
Test period, for which the pressure change rate is calculated
0:01... 1:00
Period in [minutes:seconds], ex works: 1s
“SPEd” or “Flo”: Settings
SPEd: speed unit
n:S
meter per second, m/s
kn:h
kilometer per hour, km/h
nPh
miles per hour, mph
knot
knots
FLo: Volumetric flow unit
n3:s
cubic meter per second, m3/s
n3:n
cubic meter per minute, m3/min
n3:h
cubic meter per hour, m3/h
L:S
liter per second, l/s
L:n
liter per minute, l/min
FLo: Volumetric flow - cross section
10.0 … 1999.9,
2000 … 14000
cross section in cm2
0.1000 ...
1.9999
coefficient,(Prandtl pitot tube = 1.0000 please refer to chapter
7.7)
-100.0 ...
1000.0 °C
air flow temperature
100.0 ...
1999.9 mbar
ambient pressure
0000, 000.0 …
00.00
decimal point setting
oFF, 1 …1000
minimum display, below always display 0

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Menu
Parameter
Value
Description
or
Set Output: Universal output adjustments
oFF
Interface and analog output off
SEr:
Serial interface activated
dAC:
Analog output activated
01, 11..91
Base address for serial interface communication
(only at Out = SEr)
CH 1, CH 2
or DIF CH
Channel that should be used for analog output
(only at Out = dAC)
sensor dep.
e.g.-5.00..5.00 mbar
Zero-point setting for Out = dAC: Measuring value which should
correspond to output 0 V
sensor dep.
e.g.-5.00..5.00 mbar
Slope setting for Out = dAC: Measuring value which should
correspond to output 1 V
Set Corr: Input adjustment
*
Zero adjustment/offset of sensors 1
oFF
No zero adjustment of sensors 1
Sensor dep.
e.g.-5.00..5.00 mbar
The offset of sensor 1 will be displaced by this value to compensate
for deviations of the probe or of the measuring device.
Slope adjustment of sensors 1
oFF
No slope adjustment of sensor 1
-2.000 …
2.000
The slope of sensor 1 will be changed by this factor [%] to
compensate deviations of probe or measuring device
Zero adjustment/offset of sensors 2
oFF
No zero adjustment of sensors 1
Sensor dep.
e.g.-5.00..5.00 mbar
The offset of sensor 2 will be displaced by this value to compensate
for deviations of the probe or of the measuring device.
Slope adjustment of sensors 2
oFF
No slope adjustment of sensor 2
-2.000 …
2.000
The slope of sensor 2 will be changed by this factor [%] to
compensate deviations of probe or measuring device
Set Alarm: Settings for alarm function
On/No.So
Alarm Sensor 1 on, with/without buzzer
OFF
No alarm function for Sensor 1
Sensor1-Min
... AL.1-Hi
Min-alarm-limit sensor 1 (not if AL.1 = oFF)
Sensor1-Min is lower display range limit of sensor 1
AL.1-Lo ...
Sensor1-Max
Max-alarm-limit sensor 1 (not if AL.1 = oFF)
Sensor1-Max is upper display range limit of sensor 1
On/No.So
Alarm Sensor 2 on, with/without buzzer
OFF
No alarm function for Sensor 2
Sensor2-Min
... AL.2-Hi
Min-alarm-limit sensor 2 (not if AL.2 = oFF)
Sensor2-Min is lower display range limit of sensor 2
AL.2-Lo ...
Sensor2-Max
Max-alarm-limit sensor 2 (not if AL.2 = oFF)
Sensor2-Max is upper display range limit of sensor 2
On/No.So
Alarm sensor difference on with/without buzzer
OFF
No alarm function for sensor difference
-19999 …
AL.DIF-Hi
Min-alarm-limit difference (not if AL.DIF = oFF)
AL.DIF-Lo …
19999
Max-alarm-limit difference (not if AL.DIF = oFF)

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Menu
Parameter
Value
Description
or
Set Logger: Settings for logger function
*
Selection of logger function
*
CYCL
Cyclic: cyclic logger
Stor
Store: manual recording
oFF
No logger activated
0:01 .. 60:00
Cycle time in [minutes: seconds] (for cyclic logger)
*
on/oFF
Low-power-logger with low power consumption
(only for cyclic logger and slow measuring rate)
*
Set Clock: Settings for real time clock
HH:MM
Clock: set time hours: minutes
YYYY
Year: set year
TT.MM
Date: set date day. month
rEAd Logg: Read calibration data:
p.r.t. chapter 8.1 Manual Recording (“Func-Stor”)
(*) If logger memory contains data sets parameters marked with (*) cannot be called. You
have to clear memory to change these parameters! (button 6, p.r.t. chapter 8)
(**) Parameter can only be called if corresponding sensor is plugged to connection 1. The
settings are applied to the sensor at connection 2 (if any connected).
7 Remarks to Special Features
7.1 Different Pressure Units
Depending on the connected sensors different units can be selected via menu (Unit). The measuring range
of the sensors may restrict the choice!
User-Unit
For pressure units, which are not covered by the ones printed on the display, there can be done a manual
setting for a “user-defined” unit.
Example:
To enable a GMSD 2 BR - K51 ( -1000 …2000 mbar) to display the unit kg/cm2, following settings (bold)
have to be entered:
kg/cm2
Torr
atm
at
bASE user:
bar
mbar
bar
bar
DP user:
.0000
.0000
.0000
.0000
FACt user:
1.0197
.7433
0.9869
1.0197

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7.2 Different kinds of measuring
Three different kinds of pressure measuring are supported. Two of them (P.dEt and FASt) are working with
high measuring frequency of more than 1000 measurings per second.
7.2.1 Standard measuring (slow)
Measuring rate 4 Hz, averaging and filter functions are active.
Application: Measuring of slowly changing or static pressures, e.g. measuring of leakproofness,
atmospheric pressure...
Highest accuracy, high noise immunity, low power consumption.
7.2.2 Peak detection (Peak detection)
Measuring rate >1000 Hz, the value is displayed unfiltered.
Application with logger function: Measuring of short pressure peaks or fast changing pressures with
a resolution of <1 ms. The cyclic logger function records the arithmetic mean value, the highest and
the lowest peak of the referring time interval.
Attention: higher power consumption, measuring is sensitive to noise (EMI, ...).
Measuring is sensitive to noise (EMI, ...)
and higher power consumption.
7.2.3 Fast filtered measuring (fast)
Measuring rate >1000 Hz, but the value is filtered (higher noise immunity than P.dEt, small peaks
will be filtered out), apart from that identical behavior like rAtE-P.dEt.
7.3 Water depth / level measurement

Water-proof sensors have to be used for water depth / level measurement.
Select the unit [m] for meters water column (selection mH2O) in menu “Unit“.10 m water column (=water
depth) corresponds roughly 1 bar overpressure.
Measurings can be made e.g. like described below: (for abs. pressure sensors SL has to be deactivated)
With one abs. pressure sensor: Press ‘Tara’ when sensor is at ambient air and then bring sensor to the
depth to be measured. The display shows now the depth in [m].
With two abs. pressure sensors: Sensor 2 at ambient air (does not have to be waterproof), waterproof
sensor 1 at water depth to be measured. Don’t press ‘Tara’, the depth can already read from the DIF-
display and is compensated for pressure changes in ambient air.
With one rel. pressure sensor: bring tube connection for lower press. in contact to ambient air by means
of a tube (no water contact!) and bring the sensor with its open pressure connection for higher pressure
to water depth to be measured (display and is compensated for pressure changes in ambient air).
7.4 Sea-level correction for absolute pressure sensors
The device displays the absolute pressure. This is not necessarily the same like the values given by weather
stations! The weather stations are displaying the pressure at sea level. Usually the sensor is placed above
sea level and therefore the pressure loss resulting from the actual level above sea level has to be
considered, if the value at sea level (zero) should be measured! To correct the measuring display, activate
the “Sea-Level-Function” (SL, p.r.t. chapter 6, setting is only possible, if an abs. pressure sensor is
connected to sensor connection 1). Then enter the altitude above sea level of the sensor’s location in meters
(Alti, p.r.t. chapter 6). When activated, the display shows the SL-arrow and the device displays the pressure
value at sea level.
When two absolute pressure sensors are connected, the sea level function for both corresponds to
the setting of sensor 1.

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7.5 Averaging function
The averaging function concerns the display values (LCD and interface).
It is completely independent from the averaging of the logger function FASt and P.dEt!
The averaging integrates the measuring values during a selectable period of time and then calculates the
average display value. It is independent from the selected kind of measuring (slow, fast, peak detect).
As long as not enough values have been collected (i. e. for the selected averaging time) to calculate an
average value, the upper display shows “----“, the lower display a ‘countdown‘.
During an active low-power-logging procedure the averring is always deactivated.
Function of min/max-value memory during averaging:
- If averaging is activated and slow measuring is selected (rAtE-Slo), the min-/max-value memory refers to
the average display value.
-If averaging is activated and fast measuring is selected (rAtE-FASt or P.dEt), the min-/max-value memory
refers to the internal measured values (fast peaks can be detected).
7.6 CALC: Pressure change per time dP/dt (only for sensor 1)
The CALC function “dPdt” allows displaying pressure changes per time directly. The corresponding
measuring intervals (t.int) can be freely chosen. The device automatically saves pressure values during this
period and calculates the pressure change rate “pressure change / time” from the current measuring value
and historical data.
Tare button: Historical data is deleted, calculation restarts.
Example: Tightness testing for sewage ducts according to EN 1610 with requirements less than -3 mbar/min in a
5 minutes test duration at a test pressure of 250 mbar
Equipment/presetting:
•Sealing bladder and pressure pump
•Sensor: GMSD 2 BR - K51 (measuring range -1000 … +2000 mbar)
•bASE= Pet.n (minutes) time unit for pressure change rate
•t.int = 1:00 (1 minutes) test duration, for which the pressure change rate is calculated
•Logger: Cycl, 5 sek
Procedure:
•Connect all parts, arrange all necessary sealings
•Start logger
•Charge with pressure, wait for sufficient time
•Restart calculation with “tare” button
•Current pressure value is displayed, button “set” changes to dP:dt display
•The display can give some preliminary information about the test result
•Release pressure after 5 minutes
•Stop logger
Evaluation:
Read out data logger with GSOFT3050, input at register “comment”:
Client, place of inspection, date, time, address / duct number, as-built data (duct type, nominal size, etc), test
instructions, pressures, tolerances, etc. as well as test result.
Therefore a comment sample can be prepared as file, company logo etc. can be added for printing.

t.int- setting: If there are set high values the displayed values can be easily misinterpreted,
because the displayed value responds very slowly.
The pressure change is monitored during the selected time interval t.Int and calculated referring to
the time base („bASE“). It is assumed, that the pressure continues to change the same way in the
following.
Example.: t.int = 10 sec; „bASE“ = Per.n (minutes) ; pressure change in 10 seconds = -2mbar
Resulting display CALC = -12 mbar
The displayed value is calculated: P(Tcurrent) –P(Tcurrent -t.int) / T.int
If there are not data for the whole t.int-period yet the values are extrapolated with the already
available data.

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7.7 CALC: Pitot measuring of Velocity and Flow (only for sensor 1)
7.7.1 Velocity measurement in air: “CALC SPEd”
The air velocity is calculated by means of the pressure difference at a Prandtl pitot tube or comparable
measuring setup.
with
v = velocity (m/s)
∆p = dynamic pressure (Pa) => p(A)-p(B) = measured pressure difference
s = pitot tube factor (= 1.0 for Prandtl pitot tube) value input at “COEF” in the CALC menue
= air density (kg/m³)
pa = air pressure (Pa) value input at “P.abs” in the CALC menue
Ri = gas constant (at air = 287 (J / kg • K))
T = absolute temperature (K) value input in °C at “t” in the CALC menue
(0 °C = 231.15K)
Generally the pressure differences evaluated are very small, therefore it is recommended to use pressure
sensors with high resolution.
Recommended sensors for use with a Prandtl pitot tube:
Sensor
Meas. range
Pmax
Vmin
Vmax
CALC-Menu
„dP“
CALC-Menu
„Strt“
ConF-Menu
„t.AVG“
GMSD 2,5 MR - K51
2.500 mbar
1 m/s
4 km/h
20 m/s
72 km/h
000.0
1.0
2
GMSD 25 MR - K51
25.00 mbar
5 m/s
18 km/h
64 m/s
230 km/h
0000
5
2
It is not recommended to measure velocities below Vmin, because therefore the resolution of the sensors is
too low.

Display value “-1 digit”:
If -1 digit is displayed at velocity of flow measurement the connected sensor gives a negative
pressure value -> check offset!
Velocity or flow calculation cannot be done with negative values.
7.7.2 Volumetric flow measurement in air: “CALC FLo”
The flow measurement is based on the velocity measurement (see above). Velocity multiplied with the cross-
section area (input in CALC menu by “A”) offers the volumetric flow at the selected display.

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8 Data Logger
The device supports two different logger functions:
“Func-Stor”: Manual recording by keypress “store“
Additional input of measuring point (L-Id) is needed
“Func-CYCL”: Automatic recording at intervals of set cycle time
The logger stores 9 measuring values per data set:
measuring or average (depends on function), min-peak and max-peak sensor 1
measuring or average (depends on function), min-peak and max-peak sensor 2
measuring or average (depends on function), -“CALC off”*): min-peak and max-peak sensor 1 –sensor 2
-“CALC active” *): Calculated value and dummy value
Min- and max-peak are the minimum and the maximum of the measured values since the last recording.
This allows precise analysis of the current pressure as well as pressure fluctuations.
For the evaluation of the data the software GSOFT3050 (version V3.0 or higher) has to be used. The
software also allows easy configuration and starting of the logger.
When the logger is activated (Func Stor or Func CYCL) the hold function is no more available, the key
“store” is solely used for the operation of the logger functions.
8.1 Manual Recording (“Func-Stor”)
a) Save measurements manually:
Up to 1000 measurements can be saved if logger function “Func store” is selected
(p.r.t. “Configuration”):
Press “store” shortly: data set is saved (“St. XX” is displayed shortly,
where XX is the number of the data set)
Input of measuring point “L-Id”: Selection of measuring point via keys or .
Number 0 …19999 or text assigned to number 1 …40 (comfortable assignment of texts can be
done with gratis software GMHKonfig)
Confirm input with .
One data set contains:
-Sensor 1: measuring value at the time of the recording
-Sensor 1: min-peak, max-peak since the last recording
-Sensor 2: measuring value at the time of the recording
-Sensor 2: min-peak, max-peak since the last recording
-Difference sensor 1-sensor 2: measuring value at the time of the recording
-CALC off *) Difference sensor 1-sensor 2: min-peak, max-peak since the last recording
CALC active *) Calculated value at the time of the recording and dummy value
-time and date of the recording
is displayed if logger storage is full.
*) CALC-Function: see chapter 7.6, 7.7

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b) Read manual recordings:
Saved data sets can be viewed both with PC-software GSOFT3050 and directly on the device display.
Do not change the pressure sensor if manual recording is selected and values are already
stored, because otherwise invalid data may be read-out. The pressure sensor used during the
recording has to be connected!
Press “menu” for 2 seconds: is displayed
“rEAd LoGG” is only displayed if data sets have been already stored. Otherwise the
configuration menu is displayed:
Press shortly: Change between measuring values, measuring point and
date+time of the data set
or
Change between different data sets
End display of recordings
c) Clear manual recordings:
If data sets have been stored, they can be deleted with the “store” key:
Press for 2 seconds: Call menu “Clear”
Select with or :
Clear nothing (cancel menu)
Clear all recordings
Clear the last recording
Confirm selection and quit menu “Clear”
8.2 Automatic Recording with Selectable Cycle Time (“Func CYCL“)
If logger function “Func CYCL” is selected (p.r.t. “Configuration” ) the device will automatically record
measuring values at intervals of the set cycle time.
The logger‘s cycle time can be set from 1s to 60min (p.r.t. “Configuration”).
Storable data sets: 8000
A data set contains at slow measuring rate (rAtE SLo):
-Sensor 1: measuring value at the time of the recording
-Sensor 1: min-peak, max-peak since the last recording
-Sensor 2: measuring value at the time of the recording
-Sensor 2: min-peak, max-peak since the last recording
-Difference sensor 1-sensor 2: measuring value at the time of the recording
-CALC off *) Difference sensor 1-sensor 2: min-peak, max-peak since the last recording
CALC active *) Calculated value at the time of the recording and dummy value
At data set contains at fast measuring rate (rAtE FASt and rAtE P.dEt):
-Sensor 1: arithmetic average since the last recording
-Sensor 1: min-peak, max-peak since the last recording
-Sensor 2: arithmetic average since the last recording
-Sensor 2: min-peak, max-peak since the last recording
-Difference sensor 1-sensor 2: arithmetic average since the last recording
-CALC off *) Difference sensor 1-sensor 2: min-peak, max-peak since the last recording
CALC active *) Calculated value at the time of the recording and dummy value
*) CALC-Function: see chapter 7.6, 7.7

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At measuring kind "rAtE-Slo”a power saving function is selectable: “Lo.Po”. If activated a
measurement is only done if it is also logged (i.e. no additional measurements between the saved
values). This seriously reduces the power consumption and is therefore especially appropriate for
long-term measurements (e.g. leak test) without an external power supply.
a) Start recording:
Press “store” for 2 seconds: Start Menu, press again: automatic recording will be started.
Each storage process is signaled by the short display of ‘St.XXXXX’, where XXXXX is the number of the
saved data set.
If the logger memory is full, the recording stops automatically and the display shows
If Low-Power-Logger-Function Lo.Po = on the device switches itself off as soon as the memory gets filled.
b) Stop recording:
Press “store” for 2 seconds: If recording is running the “stop” menu is displayed
Select with or .
Do not stop recording
(cancel menu)
Stop recording
Confirm selection and quit “stop” menu
If you try to switch off the device while cyclic recording is active you will be asked whether the
recording should really be stopped.
The device can only be switched off if the recording is stopped.
Auto-off function is deactivated as long as cyclic recording is active.
c) Clear recordings:
Press “store” for 2 seconds: If there are data sets stored and recording is already stopped
is displayed
Select with or to call the clear-menu
Select with or .
Clear nothing (cancel menu)
Clear all recordings
Clear the last recording
Confirm selection and quit menu “Clear”

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9 Universal Output
The output can be used either as serial interface (for USB 5100 interface converter) or as analog output
(0-1V). If the output is not needed, it is strongly recommended to deactivate it (Out oFF) to lower power
consumption. This increases battery life time.
If the device is used together with interface adapter USB 5100 the device is supplied from the interface.
Pin assignment:
1: external supply +5V, 50 mA
2: GND
3: TxD/RxD (3.3V Logic)
4: +UDAC, analog output

Only suitable adaptor cables are
permitted (accessories)!
9.1 Interface
The device can be connected to a USB interface of a PC by the electrically isolated interface converter
USB 5100 (accessory). The data is transmitted binary-coded and protected against transmission errors by
complex safety mechanism (CRC).
The following standard software packages are available:
GSOFT3050: Operating and evaluation software for the integrated logger function
EBS20M / -60M: 20-/60-channel software for measuring value display
GMHKonfig: Configuration Software (for free on internet)
In case you want to develop your own software we offer a GMH3000-development package including:
a universally applicable Windows functions library ('GMH3x32e.DLL') with documentation, can be used
by all ‘established’ programming languages, suitable for:
Windows XP™, Windows Vista™, Windows 7™
Programming examples Visual Basic 4.0™, Delphi 1.0™, Testpoint™ etc.
The device has 9 channels:
-Channel 1: current measuring value (sensor 1) and base address
-Channel 2: min peak (sensor 1)
-Channel 3: max peak (sensor 1)
-Channel 4: current measuring value (sensor 2)
-Channel 5: min peak (sensor 2)
-Channel 6: max peak (sensor 2)
-Channel 7: current measuring value (difference sensor 1 –sensor 2)
-Channel 8: min peak (difference sensor 1 –sensor 2) or CALC-value
-Channel 9: sensor 1 max peak (difference sensor 1 –sensor 2) or Dummy, if CALC is active
The measuring-/ alarm- and display range values read back from the interface are always in
the selected measurement unit (mbar, bar...)!

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9.2 Analog output
An analog voltage 0-1V can be tapped at the universal output connector (mode: “Out dAC”).
The analog output can be easily scaled with DAC.0 and DAC.1.
Please take care not to load the analog output too heavily, otherwise the output value will be distorted and
the power consumption will rise. Loads up to approx. 100 kOhm are unproblematic.
If the displayed value goes beyond DAC.1 the output voltage will be 1V.
If the displayed value falls below DAC.0 the output voltage will be 0V.
In error case (Err.1, Err.2, ----, etc.) the output voltage will be slightly higher than 1V.
The interface converter USB 5100 has a screw/plug connection; therefore no further cable is necessary if
USB 5100 is used.
10 Input Adjustment
The zero point and slope of each measuring inputs can be adjusted with the parameters offset (“OFFS”) and
scale (“SCAL”).
A reasonable adjustment presumes reliable references (e.g. ice water, controlled precision water bath, etc.).
If the inputs are adjusted (i.e. offset and scale are different from default settings) the device will shortly
display “Corr” after turned on.
Default setting for offset and scale are ‘off’ = 0.0, i.e. inputs are not changed.
Zero point correction:
Displayed value = measured value –OFFS
Zero point and slope correction:
Displayed value = (measured value –OFFS) * (1 + SCAL / 100 )
11 Pressure Connection to the Sensors
The device is designed to be connected to the sensors of the GMSD/GMXD...-series without a new
calibration being necessary. Therefore a great variety of replaceable sensors of e.g. -1.999 ... 2.500 mbar
relative up to 0 ... 1000 bar absolute pressure can be connected to the device.
Relative pressure sensors (types: GMSD ... MR - K51, GMSD ... BR - K51)
For measurements of over- or under pressure:
Pressure sensors GMSD 2,5 MR - K51, GMSD 25 MR - K51 and GMSD 350 MR - K51 allow for
measurements of under pressure up to the entire over pressure measuring range by re-plugging the tube
to pressure port “A”.
Please note that all values are displayed as positive values. No minus sign will be shown. (Example for
GMSD 25 MR - K51: For tube connection “B” the measuring range covers -19.99 to 25.00 mbar. If you
replug to port “A”under pressure measurements down to -25.00 mbar could be carried out with the
display showing the value 25.00 (no minus sign).
For measurements of pressure differences:
Connect both plastic tubes with an internal diameter of 4 mm to pressure port “B”and “A”; make sure to
apply higher pressure to port “B”.
Absolute pressure sensors (types: GMSD ... BA - K51)
Connect plastic tube with an inner diameter of 4 mm to pressure port “A”. (Port “B”is not used.)
Stainless steel sensors (types: MSD ... MRE, MSD ... BRE, MSD ... BAE)
For measurements of over-, under- or absolute pressure screw sensor to G1/2" pressure terminal or plug
plastic tube to a suitable adapter. Connection to instrument: Use cable MSD-K51.
Pressure measurements with two sensors
Pressure differences of any sensor combinations can be measured by means of the calculation sensor1 –
sensor2 (DIF).

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12 Alarm (“AL.”)
There are 3 possible settings:
off (AL.oFF), on with buzzer (AL.on), on without buzzer (AL.no.So).
Alarm is given in the following cases (if alarm active, AL.on or AL.no.So):
-Lower alarm boundary (AL. Lo) under-run
-Upper alarm boundary (AL. Hi) over-rum
-Sensor error
-Low battery (bAt)
-Err.7: system error (always with buzzer!)
In case of an alarm (and when polling the interface) the prio-flag is set in the returned interface message.
13 Real Time Clock (“CLOC”)
The real time clock is used for chronological assignment of the logger data and calibration points. Please
check the settings when necessary.
14 Accuracy Check / Adjustment Service
You can send the device to the manufacturer for adjustment and inspection.
Calibration certificate - DKD certificate - official certifications:
If the measuring instrument is supposed to receive a calibration certificate, it has to be sent to the
manufacturer (declare test points).
If the device is certificated together with a suitable sensor very high overall accuracies are possible.
Basic settings can only be checked and –if necessary –corrected by the manufacturer.
A calibration protocol is enclosed to the device ex works. This documents the precision reached by the
production process.
15 Replacing Batteries
Before changing batteries, please read the following instruction and follow it step by step.
Not following the instruction may cause harm to the instrument or the
protection against ingress of water and dust may be lost!
Avoid unnecessary opening of the instrument!
1. Open the 3 Phillips screws at the backside of the instrument.
2. Lay down the still closed instrument, so that the display side
points upwards.
The lower half of the housing incl. the electronics should be kept
lying down during battery change.
This avoids loss of the sealing rings of the screw holes..
3. Lift upper half of housing. Keep an eye on the six function keys,
to be sure not to damage them.
4. Change carefully the two batteries (Type: AAA).
5. Check: Are the 3 sealing rings placed in the housing?
Is the circumference seal of the upper half sound and clean?
6. Close the housing, taking care that it is positioned correctly,
otherwise the sealing may be damaged. Afterwards press the
two halves together, lay the instrument with display pointing
downwards and screw it together again
Take care to screw only until you feel increasing resistance,
higher screwing force does not result in higher water
protection!
do not
touch
circuit

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16 Error and System Messages
Display
Description
What to do?
or Err.9
No sensor connected
Switch off device and connect sensor
Connected sensor or device defective
If 2nd sensor available, check if device is ok. Return
defective device/sensor to manufacturer for repair
Value extremely out of measuring range
Check: pressure not within sensor range?
No display or
confused
characters,
device does not
react on keypress
Battery empty
Replace battery
Mains operation: wrong voltage or polarity
Check power supply, replace it when necessary
System error
Disconnect battery and power supplies, wait shortly,
then reconnect
Device defective
Return to manufacturer for repair
Err.1
Measured value above allowable range
Check: pressure not within sensor range?
-> measuring value to high!
Sensor defective
Return to manufacturer for repair
Err.2
Measured value below allowable range
Check: pressure not within sensor range?
-> measuring value to low!
Sensor defective
Return to manufacturer for repair
Err.3
Display range overflow
Check: value above 19999 -> to high to be displayed
Err.4
Display range underflow
Check: value below -19999 (Tara?) -> to low
Er.11
Value could not be calculated
Choose different unit
Calculation overflow happened
Choose different unit
Err.7
System error
Return to manufacturer for repair
––––
Sensor not present / recognised
reconnect sensor,
during logging: stop the logger and restart it
could not calculate value
suitable sensor / unit combination necessary
If “bAt” is flashing the battery will be exhausted soon. Further measurements are possible for short time. If
“bAt” is displayed continuously the battery is ultimately exhausted and has to be replaced. Further
measurements aren’t possible any more.
17 Reshipment und Disposal
17.1 Reshipment
_DANGER
All devices returned to the manufacturer have to be free of any residual of measuring media
and/or other hazardous substances. Measuring residuals at housing or sensor may be a risk for
persons or environment
Use a adequate transport package for reshipment, especially for fully functional devices. Please
make sure that the device is protected in the package by enough packing materials.
17.2 Disposal instructions
Batteries must not be disposed in the regular domestic waste but at the designated collecting points.
The device must not be disposed in the unsorted municipal waste! Send the device directly to us
(sufficiently stamped), if it should be disposed. We will dispose the device appropriate and environmentally
sound.