GREISINGER GMH 3251 User manual

H76.0.02.6C-04
GHM GROUP - Greisinger
GHM Messtechnik GmbH | Hans-Sachs-Str. 26 | 93128 Regenstauf | GERMANY
Tel.: [phone] | [email protected] | www.greisinger.de
Operating manual
Quick-Response
Double / Difference Thermometer
as of version 4.0
GMH 3251

Please carefully read these instructions
before use!
WEEE-Reg.-Nr. DE 93889386

Please consider the safety instructions!

Please keep for future reference!

H76.0.02.6C-04 Operating Manual GMH 3251 page 2 of 18
_____________________________________________________ _____________________________________________________________________________
Index
1GENERAL NOTE ...............................................................................................................3
2SAFETY................................................................................................................................3
2.1 INTENDED USE ..................................................................................................................3
2.2 SAFETY SIGNS AND SYMBOLS ............................................................................................3
2.3 SAFETY GUIDELINES..........................................................................................................4
3PRODUCT SPECIFICATION...........................................................................................5
3.1 SCOPE OF DELIVERY ..........................................................................................................5
3.2 OPERATION AND MAINTENANCE ADVICE...........................................................................5
4HANDLING .........................................................................................................................6
4.1 DISPLAY............................................................................................................................6
4.2 BASIC OPERATION.............................................................................................................6
4.3 CONNECTIONS...................................................................................................................7
4.4 POP-UP CLIP......................................................................................................................7
5START OPERATION.........................................................................................................8
6CONFIGURATION.............................................................................................................8
7REMARKS TO SPECIAL FEATURES .........................................................................10
7.1 TARE FUNCTION..............................................................................................................10
7.2 BASE ADDRESS (’ADR.’) .................................................................................................10
7.3 POWER OFF TIME.............................................................................................................10
7.4 ALARM............................................................................................................................10
7.5 REAL TIME CLOCK..........................................................................................................10
8OPERATION OF LOGGER............................................................................................11
8.1 „FUNC-STOR“: STORING SINGLE MEASUREMENTS..........................................................11
8.2 „FUNC-CYCL“: AUTOMATIC RECORDING WITH SELECTABLE LOGGER-CYCLE-TIME ...12
9OUTPUT.............................................................................................................................13
9.1 SERIAL INTERFACE..........................................................................................................13
9.2 ANALOGUE OUTPUT –SCALING WITH DAC.0 AND DAC.1.............................................15
10 ADJUSTMENT...............................................................................................................15
10.1 ZERO DISPLACEMENT SENSOR 1('OFS.1') OR SENSOR 2('OFS.2')...............................15
10.2 SCALE CORRECTION SENSOR 1('SCL.1') OR SENSOR 2('SCL.2').................................15
10.3 CORRECTION FOR SURFACE MEASURING SENSOR 1(’SCF.1’) OR SENSOR 2(’SCF.2’) 15
10.4 CALIBRATION SERVICES...............................................................................................16
11 FAULT AND SYSTEM MESSAGES...........................................................................16
12 RESHIPMENT AND DISPOSAL.................................................................................16
12.1 RESHIPMENT.................................................................................................................16
12.2 DISPOSAL .....................................................................................................................17
12.3 DECOMMISSIONING ......................................................................................................17
13 SPECIFICATION...........................................................................................................17

H76.0.02.6C-04 Operating Manual GMH 3251 page 3 of 18
_____________________________________________________ _____________________________________________________________________________
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.
2 Safety
2.1 Intended Use
This device is designed for the mobile use or the stationary operation in a controlled
electromagnetic environment (lab).
This device is designed for temperature measurement.
You can plug in up to 2 thermocouple sensors with Miniature-DIN-plug.
If you use two sensors, you can measure two different temperatures as well as the
difference between them.
The device features a lot of useful features as for example min-/max-alarm, hold,
correction factor for surface measurement, interface etc.
Personnel which starts up, operates and maintains the device has to have sufficient
knowledge of the measuring procedure and the meaning of the resulting measured
values, this manual delivers a valuable help for this. The instructions of the manual
have to be understood, regarded and followed.
To be sure, that there´s no risk arising due to misinterpretation of measured values,
the operator must have further knowledge in case of doubt - the user is liable for any
harm/damage resulting from misinterpretation due to insufficient knowledge.
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 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 labelled in this document with the followings signs:
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, possibly cause incorrect measurement or provoke
unforeseen reactions at non-observance.

H76.0.02.6C-04 Operating Manual GMH 3251 page 4 of 18
_____________________________________________________ _____________________________________________________________________________
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
chapter 13 Specification.
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. 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.
4. 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.
5. This device is not constructed for use in medical applications.
6. This device must not be run with a defective or damaged power supply
unit. Danger to life due to electrical shock!
7. 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.
8. Temperature sensor:
There is a risk of stitch injury by using insertion probs. When measuring
high temperatures there is a risk of burn, also due to residual heat of
the sensor tube.
9. Consider when measuring in food:
The device housing is not construed for the permanent contact with
food. Keep in mind to use temperature-probes witch are suitable for the
use in food only.

H76.0.02.6C-04 Operating Manual GMH 3251 page 5 of 18
_____________________________________________________ _____________________________________________________________________________
3 Product Specification
3.1 Scope of delivery
The scope of supply includes:
Device with battery
Operating manual
3.2 Operation and maintenance advice
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.
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.
Mains operation with power supply
When using a power supply please note that operating voltage has to be
10.5 to 12 V DC.
Do not apply overvoltage!! Cheap 12V-power supplies often have
excessive no-load voltage.
We, therefore, recommend using regulated voltage power supplies.
Trouble-free operation is guaranteed by our power supply GNG10/3000.
Prior to connecting the power supply to the mains, make sure that the operating
voltage stated at the power supply is identical to the mains voltage.
Treat device and sensor carefully. Use only in accordance with above specification.
(do not throw, hit against etc.). Protect plug and socket from soiling.
Connecting/changing sensors
To disconnect thermocouple sensor plug do not pull at the cable but at the
plug
Selection of types of thermocouples: Prior to carrying out a
measurement make sure to check if device is set to the thermocouple
type used (type is shown on the display shortly after unit has been
switched on). Unless the correct thermocouple is set, temperature
measurements will be incorrect!

H76.0.02.6C-04 Operating Manual GMH 3251 page 6 of 18
_____________________________________________________ _____________________________________________________________________________
4 Handling
4.1 Display
1
Main display: measuring value of sensor 1
2
Arrows show display options.
3
Secondary display: measuring value of sensor 2
or difference sensor 1 –sensor 2
4
Corr: appears if offset- , scale correction or
correction for surface measurement is <> state of
delivery.
5
Alarm: appears with alarm condition on
6
Tare: appears if tare-function is active.
Only with difference measurement.
7
Logg: appears if logger function is chosen, flashes
while logger is running
4.2 Basic Operation
On / Off
+
min/max measuring:
press short: shows the min./max. value
press again: hides min./max. value
press 2 sec.: clears particular value
Tare: (only with ´DIF´-display and two
connected sensors)
press short: the difference CH1 –CH2
will be set to 0
press 2 sec.: deactivates tare-function
Set/Menu:
press short: Choose secondary display:
Sensor 2 or difference
sensor 1 –sensor 2
press long: calling of configuration
Store/Quit:
press short: hold-function, the last
measuring value will be held.
press again: hold-function canceled
at active logger: invokes logger functions
Please Note: Activating/deactivating tare clears the max- & min-memories.

H76.0.02.6C-04 Operating Manual GMH 3251 page 7 of 18
_____________________________________________________ _____________________________________________________________________________
4.3 Connections
Output: Connection for optically isolated
interface adapter or for analog
output (please refer to chapter 9.2)
Sensor Connection CH1: channel 1
Sensor Connection CH2: channel 2
Power supply: the mains adapter socket is located at the left side of the
device.
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

H76.0.02.6C-04 Operating Manual GMH 3251 page 8 of 18
_____________________________________________________ _____________________________________________________________________________
5 Start Operation
Connect sensor and turn on device via key.
After segment test the device displays some configuration:
• If the surface correction factor is adjusted, the display will show
„SCF.x“ and its value shortly.
After that, the device is ready for measuring.
6 Configuration
To change device settings, press Set (key 4) for 2 seconds. This will call the
configuration menu (main display: „SEt“).
Pressing key Set changes between the menus, pressing (key 3) jumps to the
referring parameters, which can be selected with key (key 3).
The parameters can be changed with (key 2) or (key 5).
Pressing Set again jumps back to the main configuration menu and saves the
settings.
Store (key 6) finishes the configuration and returns to standard measuring operation.
Menu
Parameter
Values
Meaning
KEY
Menu
KEY

KEY
or 
rEAd
LoGG
rEAd Logg: Read the single-logger data
refer chapter 8.1 „Func-Stor“: Storing Single Measurements
SEt
ConF
Set Configuration: Generic Configurations
tYPE
ni.cr
J
S
T
N
B
E
Selection Thermocouple:
Type K: NiCr-Ni
Type J: Fe-CuNi
Type S: Pt10Rh-Pt
Type T: Cu-CuNi
Type N: NiCrSi-NiSi
Type B: Pt30Rh-Pt6Rh
Type E: NiCr-CuNi
*
rES
0.1°
Resolution: 0,1°C or °F
*
1°
Resolution: 1°C or °F
Unit
°C
Values in °C
*
°F
Values in °F
P.oFF
1-120
Auto Power Off time in minutes
oFF
Auto Power Off deactivated
Out
oFF
Function of the output: No output function, lowest power
consumption
SEr
Output is serial interface
dAC
Output is analogue output 0...1V
Adr.
01,11..91
Base address of interface (if Out = SEr)
dAC.
CH1, CH2
or CH DIF
Choice of the input to be the source for the analogue output
(if Out = dAC)
dAC.0
Min meas. range
..
Max meas. range
Enter desired value at which the analogue output potential
should be 0V (if Out = dAC)
dAC.1
Min meas. range
..
Max meas. range
Enter desired value at which the analogue output potential
should be 1V (if Out = dAC)

H76.0.02.6C-04 Operating Manual GMH 3251 page 9 of 18
_____________________________________________________ _____________________________________________________________________________
SEt
Set Calibration: Adjustment of Sensors
Corr
OFS.1
-10.0°C..10.0°C or
-18.0°F..10.0°F
The offset of sensor 1 will be displaced by this value to
compensate for deviations in the Sensor or in the
measuring device.
oFF:
Zero point displacement is deactivated (=0.0°)
OFS.2
-10.0°C..10.0°C or
-18.0°F..10.0°F
The offset of sensor 2 will be displaced by this value to
compensate for deviations in the Sensor or in the
measuring device.
oFF:
Zero point displacement is deactivated (=0.0°)
SCL.1
-5.00..5.00 %
The measuring scale of sensor 1 will be changed by this
factor [%] to compensate deviations of temperature probe
or measuring device.
oFF:
Correction factor is deactivated (=0.000)
SCL.2
-5.00..5.00 %
The measuring scale of sensor 2 will be changed by this
factor [%] to compensate deviations of temperature probe
or measuring device.
oFF:
Correction factor is deactivated (=0.000)
SCF.1
0.950..1.200
Correction value for surface measurement of sensor 1.
(related to ambient temperature of the measuring device)
See chapter 10.3
oFF:
Surface correction factor is deactivated (=1.000)
SCF.2
0.950..1.200
Correction value for surface measurement of sensor 1.
(related to ambient temperature of the measuring device)
See chapter 10.3
oFF:
Surface correction factor is deactivated (=1.000)
SEt
Set Alarm: Settings Of Alarm Function
AL.
AL
On
Alarm on, with buzzer sound
no.So
Alarm on, without buzzer sound
oFF
no alarm function
AL.
CH 1
Alarm input Sensor 1 (not when AL. = oFF)
CH 2
Alarm input Sensor 2 (not when AL. = oFF)
CH 1.2
Common alarm Sensor 1 and Sensor 2 (not when AL. =
oFF)
DIF
Alarm input sensor difference (not when AL. = oFF)
AL.Lo
Min meas. range ..
AL.Hi
Min alarm rail of the input set under “AL.” (not when AL.2 =
oFF)
AL.Hi
AL-Lo... Max meas.
range
Max alarm rail of the input set under “AL.” (not when AL.2 =
oFF)
SEt
LoGG
Set Logger: Configuration Of Logger Function
*
Func
CYCL
Cyclic: logger function ‚cyclic logger‘
**
Stor
Store: logger function ‚individual value logger‘
**
oFF
no logger function
**
CYCL
1..3600
Cycle time of cyclic logger [seconds]
*
SEt
CLOC
Set Clock: Setting Of Real Time Clock
CLOC
HH:MM
Clock: Setting of time hours:minutes
dAtE
TT.MM
Date: day.month
YEAr
YYYY
Year
Note: When using the logger function some settings in the menu may not be accessible. Please
note (*) and (**).
(*) This menu can only be invoked if the logger is not running! If parameters
should be changed, the logger has to be stopped before! (key 6, p.r.t.
chapter 8)
(**) This menu can only be invoked if the logger memory contains no data! If
parameter should be changed the logger memory has to be cleared
before! (key 6, p.r.t. chapter 8)

H76.0.02.6C-04 Operating Manual GMH 3251 page 10 of 18
_____________________________________________________ _____________________________________________________________________________
7 Remarks To Special Features
7.1 Tare Function
The tare function is used to set the DIF-display to zero, which is especially important
when monitoring temperature differences. If the tare key is pressed for more than 2
seconds DIF = CH1-CH2 will be restored. This function as well as the DIF-display
can only be used with two sensors connected. If the tare function is activated, this will
be shown by the tare arrow in the display. Tare has no effect on logger recordings.
7.2 Base Address (’Adr.’)
Using the interface converter GRS3105 it is possible to connect several instruments
to a single interface. As a precondition the base addresses of all devices must not be
identical. In case several devices will be connected via one interface make sure to
configure the base addresses accordingly. Channel 1 will be addressed by the base
address set, channels 2 and 3 will have the following addresses.
(Example: base address 21 - channel 1 = 21, channel 2 = 22, channel 3 = 23)
7.3 Power off Time
If there won’t be pressed any key and no interface communication takes place for the
time of the power off time setting (P.Off), the device will be switched off automatically
to save battery power.
If P.oFF = oFF then the automatic switch off is deactivated.
7.4 Alarm
There are three possible settings: Alarm off (AL. oFF), on with horn sound (AL. on),
on without horn sound (AL. no.So). Following conditions will display an alarm, when
the function is activated (on or no.So):
-Value is below lower (AL. Lo) or above upper alarm rail (AL.Hi).
-Sensor error (Sens Erro)
-Low battery (bAt)
-Fe 7: System error (always with sound)
In case of an alarm and when polling the interface the prio-flag is set in the returned
interface message.
7.5 Real Time Clock
The real time clock is used for the logger function: Recorded values are also
containing the point of time, when they were measured. Please check the settings
when necessary. If the battery was replaced the referring menu ‚CLOC‘ will
automatically be started

H76.0.02.6C-04 Operating Manual GMH 3251 page 11 of 18
_____________________________________________________ _____________________________________________________________________________
8 Operation Of Logger
The device supports two different logger functions:
„Func-Stor“: each time when „store“ (key 6) is pressed a measurement will be
recorded.
„Func-CYCL“: measurements will automatically be recorded each interval, which
was set in the logger menu ‚CYCL‘ until the logger will be stopped or
the logger memory is full. The recording is started by pressing
„Store“ 2 seconds.
The logger records 3 measurement results each time:
Value sensor 1, value sensor 2 and difference sensor 1 –sensor 2
For the evaluation of the data the software GSOFT 3050 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 6 is solely used for the operation of the logger functions.
8.1 „Func-Stor“: Storing Single Measurements
Each time when „store“ (key 6) is pressed a measurement and its time stamp will be
recorded.
The recorded data can be viewed either in the display (when calling the configuration
an additional menu „REAd LoGG“ is displayed, see below) or by means of the
interface and a PC with GSOFT3050-software.
Please note: For the Func-Stor-logging function it is not allowed to change the
sensor after values are stored, otherwise invalid data could be read out.
Max. number of measurings: 1000
A measuring contains: - sensor 1, current measuring value at the time of recording
- sensor 2, current measuring value at the time of recording
- difference sensor 1 - sensor 2, current measuring value
at time of recording
- time and date of the recording
After each recording „St. XX“ will be displayed for a short time. XX represents the
number of the recording.
If logger memory contains recordings already:
When „Store“ is pressed for 2 seconds, the choice for clearing the logger memory will
Be displayed:
The selection can be made by (key 2) and (key 5). "store" (key 6) enters the
choice.
If the logger memory is full, the display will show:
Viewing Recorded Measurings
Within the „LoGG Stor“ function the measurings can be viewed directly in the display
not only by means of a computer (like at „Func CYCL“): press 2 seconds „Set“ (key
4): The first menu displayed now is „rEAd LoGG“ (read logger data). After pressing 
Clear all
recording
s
Clear the last
recording
Clear nothing
(cancel menu)

H76.0.02.6C-04 Operating Manual GMH 3251 page 12 of 18
_____________________________________________________ _____________________________________________________________________________
(key 3) the measurement recorded last will be displayed, changing between the
different values referring to the measurement also is done by pressing .
Changing the measurement is done by pressing the keys or .
8.2 „Func-CYCL“: Automatic Recording With Selectable Logger-Cycle-
Time
The Logger-Cycle-Time is settable (p.r.t. Configuration). For example „CYCL“ = 60: A
measuring is recorded after each 60 seconds.
Max. number of measurings: 10000 (at max. 64 recording sequences)
Cycle time: 1...3600 seconds (=1h), selectable in the configuration
A measuring contains:
- sensor 1, current measuring value at the time of recording
- sensor 2, current measuring value at the time of recording
- difference sensor 1 –sensor 2,
current measuring value at time of recording
Starting a recording:
By pressing "Store" (key 6) for 2 seconds the logger operation will be called. The
display will show:
By pressing "Store" again the recording will be initiated.
After that the display shows ‘St.XXXX‘ for a short time whenever a measuring is
recorded.
XXXX is the number of the measuring 1..10000.
If the logger memory is full, the display will show: The recording automatically
will be stopped.
Stopping the recording manually:
By pressing "Store" (key 6) the recording can be stopped manually. Then the following choice appears:
The selection can be made by (key 2) and (key 5). "Quit" (key 6) enters the
choice.
Note: If you try to switch off the instrument in the cyclic recording operation you will be
asked once again if the recording is to be stopped.
The device can only be switched off after the recording has been stopped!
The Auto-Power-Off-function is deactivated during recording!
Stop the
recording
Do not stop the
recording

H76.0.02.6C-04 Operating Manual GMH 3251 page 13 of 18
_____________________________________________________ _____________________________________________________________________________
Clear Recordings:
By pressing "Store" (key 6) for 2 seconds the logger operation will be called.
The display will show: By pressing the keys (key 2) or (key 5) the display
will change to .
When „Store“ is pressed, the choice for clearing the logger memory will be displayed:
Clear all
recordings
Clear the last
recording
sequence
Clear nothing
(cancel menu)
The selection can be made by (key 2) and (key 5). "Quit" (key 6) enters the
choice.
9 Output
The output can be used as serial interface (for USB 3100, USB 3100 N, GRS
3100 or GRS 3105 interface adapters) or as analog output (0-1V).
If none of both is needed, we suggest to switch the output off, because battery life
then is extended.
9.1 Serial Interface
By means of the serial interface and a suitable electrically isolated interface adapter
(USB 3100, USB 3100 N, GRS 3100 or GRS 3105) the device can be connected to a
computer for data transfer.
With the GRS 3105 up to 5 devices of the GMH 3xxx- series can be connected to one
interface (see also manual of GRS 3105). As a precondition the base addresses of all
devices must not be identical, make sure to configure the base addresses accordingly
(refer menu point “Adr.” in chapter 6).
To avoid transmission errors, there are several security checks implemented e.g.
CRC.
The following standard software packages are available:
GSOFT3050: Operation and read out of logger function, data display in diagrams
and tables
GMHKonfig: Software for a comfortable editing of the device
EBS 20M / 60M: 20-/60-channel software to display the measuring values
In case you want to develop your own software, we offer a GMH3000-development
package including:
A universally applicable Windows functions library ('GMH3000.DLL') with
documentation that can be used by the most programming languages. Suitable for
Windows XP™, Windows Vista™, Windows 7™, Windows 8 / 8.1™, Windows 10™
Programming examples Visual Studio 2010 (C#, C++ and VB), LabView™ etc.
In addition to the operation at a PC the device can be operated with the GAM 3000
device, to use the alarm function for simple supervision and controlling applications.
Just connect a GAM 3000 to the interface, activate the alarm function of the GMH
and the relays output is operating.

H76.0.02.6C-04 Operating Manual GMH 3251 page 14 of 18
_____________________________________________________ _____________________________________________________________________________
The device has 3 channels:
-Channel 1: sensor 1 current measuring value (base address)
-Channel 2: sensor 2 current measuring value
-Channel 3: difference sensor 1 - sensor 2 current measuring value
Note: The measuring-/ alarm- and display range values read back from the
interface are always in the selected measurement unit!
Supported interface functions
Channel
Code
Function
1
2
3
x
x
x
0
Read measurement value
x
x
x
3
Read system state
x
12
Read ID number
x
32
Read configuration flag
BitAlarmOn: 1, BitAlarmSound:3;
BitLoggerOn:50; BitCyclicLogger:51;
BitLowPowerLogger:52
x
160
Set configuration flag (refer to 32)
x
174
Delete min. value
x
175
Delete max. value
x
x
x
176
Read min measuring range
x
x
x
177
Read max measuring range
x
x
x
178
Read measuring range unit
x
x
x
179
Read measuring range decimal point
x
x
x
180
Read kind of measuring of sensor
x
194
Set display unit
x
195
Set decimal point in display
x
x
x
199
Read kind of measuring of display
x
x
x
200
Read min display range
x
x
x
201
Read max display range
x
x
x
202
Read display range - unit
x
x
x
204
Read display range - decimal point
x
208
Read # of channels
x
x
214
Read scale correction
x
x
215
Set scale correction
x
x
216
Read offset correction
x
x
217
Set offset correction
x
x
218
Read correction factor for surface measurement
x
x
219
write correction factor for surface measurement
x
229
Logger: Read state
x
231
Logger: Read stop time
x
233
Read real time clock (CLOC)
x
234
Set real time clock (CLOC)
x
236
Read logger memory size
x
229
Logger: Read state
x
231
Logger: Read stop time
x
233
Read real time clock (CLOC)
x
234
Set real time clock (CLOC)
x
236
Read logger memory size
x
237
Read logger filecount
x
238
Read logger filepointer
x
239
Read logger file info
x
240
Reset
x
254
Program version
x
260
Logger: read data of STOR Logger
x
x
x
263
Read logger channel info

H76.0.02.6C-04 Operating Manual GMH 3251 page 15 of 18
_____________________________________________________ _____________________________________________________________________________
9.2 Analogue Output –Scaling with DAC.0 and DAC.1
Note: Analogue output can not be used during logger recordings
With the DAC.0 and DAC.1 values the output can be rapidly scaled to your efforts.
Keep in mind not to connect low-resistive loads to the output, otherwise the output
value will be wrong and battery life is decreased. Loads above ca 10kOhm are
uncritical. The connection cable may not be longer than 3m.
If the display exceeds the value set by DAC.1, then the device will apply 1V to the
output
If the display falls below the value set by DAC.0, then the device will apply 0V to the
output
In case of an error (Err.1, Err.2, no sensor, etc.) the device will apply slightly above
1V to the output.
plug wiring:
GND
Attention!
the 3rd contact has to be left floating!
Only stereo plugs are allowed!
+Uout
10 Adjustment
10.1 Zero Displacement Sensor 1 ('OFS.1') or Sensor 2 ('OFS.2')
A zero displacement can be carried out for the measured value:
value displayed = value measured - offset
Standard setting: 'off' = 0.0°, i.e. no zero displacement will be carried out. Together
with the scale correction (see below) this factor is mainly used to compensate for
sensor deviations. Input is in the display unit.
10.2 Scale Correction Sensor 1 ('SCL.1') or Sensor 2 ('SCL.2')
This setting influences the scale of the measuring (factor is in %):
displayed value = measured value * (1+Scal/100)
Standard setting: 'off' =0.000, i.e. value is not corrected. Together with the zero
displacement (see above) this factor is mainly used to compensate for sensor
deviations.
10.3 Correction for surface measuring Sensor 1(’SCF.1’)
or Sensor 2 (’SCF.2’)
The correction value refers to the temperature difference between the device- /
ambient temperature and the temperature determined by the thermocouple.
Display = device temperature + (measured temperature –device temperature) * Corr
Standard setting: ’off’ =1.000
This factor is used to compensate for losses of transfer in case of surface
measurements, occurring if the object to be measured is extremely hot but will be
cooled by lower ambient temperatures. The same can be true for sensors with a large
mass. Unless ’off’ is set, this value will be displayed shortly after the device is

H76.0.02.6C-04 Operating Manual GMH 3251 page 16 of 18
_____________________________________________________ _____________________________________________________________________________
switched on; during operation it will be identified by means of the Corr-arrow in the
display
10.4 Calibration Services
Calibration certificates –DKD-certificates –other certificates:
If device should be certificated for its accuracy, it is the best solution to return it to the
manufacturer.
Only the manufacturer is capable to do efficient recalibration if necessary to get
results of highest accuracy!
11 Fault and System Messages
Display
Meaning
What to do?
Low battery power, device will only continue
operation for a short period of time
Replace battery
Battery empty
Replace battery
Mains operation without battery: wrong
voltage
Check power supply, replace it when necessary
No sensor connected
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: right thermocouple selected.
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: correct thermocouple selected.
Temperature not within sensor range?
-> measuring value to high!
Sensor defective
Return to manufacturer for repair
Err.2
Measured value below allowable range
Check: correct thermocouple selected.
Temperature not within sensor range?
-> measuring value to low!
Sensor defective
Return to manufacturer for repair
Err.3
Display range overflow
Check: value above 1999.9 -> too high to be
displayed
Err.4
Display range underflow
Check: value below -1999.9 (Tara?) -> too low
Er.11
Value could not be calculated
A value, that is necessary for the calculation, is not
available (no sensor) or faulty (over- / underflow
Calculation overflow happened
Choose different unit
Err.7
System error
Check allowed working temperature of the device
Return to manufacturer for repair
12 Reshipment and disposal
12.1 Reshipment
All devices returned to the manufacturer have to be free of any residual
of measuring media and other hazardous substances.
Measuring residuals at housing or sensor may be a risk for persons or
environment

H76.0.02.6C-04 Operating Manual GMH 3251 page 17 of 18
_____________________________________________________ _____________________________________________________________________________
Use an 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.
Add the completed reshipment form of the GHM website
http://www.ghm-messtechnik.de/downloads/ghm-formulare.html.
12.2 Disposal
Dispense exhausted batteries at destined gathering places The device
must not be disposed in the unsorted municipal waste! Send the device
directly to us (sufficiently stamped), considering the above if it should be
disposed. We will dispose the device appropriate and environmentally
sound.
Private user can return the device at the municipal collection points for
small electrical appliances.
12.3 Decommissioning
When decommissioning, connections must not be in a condition that causes the
connected evaluation electronics (e.g. interface) to trigger unexpected switching
operations.
13 Specification
Thermocouples: J, K, N, S, T, E, B
Resolution: 0.1°C or 1°C 0.1°F or 1°F
Measuring range:
Type K (NiCr-Ni): -220.0 ... +1372.0°C -364.0 ... +2502.0°F (*
Type J (Fe-CuNi): -200.0 ... +1100.0°C -328.0 ... +2021.0°F (*
Type T (Cu-CuNi): -200.0 ... +400.0° -328.0... +752.0°F
Type N (NiCrSi-NiSi): -200.0 ... +1300.0° -328.0 ... +2372.0°F (*
Type S (Pt10Rh-Pt): -50.0 ... +1768.0°C -58.0 ... +3215.0°F (*
Type E (NiCr-CuNi): -60.0 ... +850.0°C -76.0 ... +1562.0°F
Type B ( Pt30Rh-Pt6Rh ): +300 ... +1750°C +572 ... +3182°F (*
*) values via interface, the device displays up to 1999.9 °F
Accuracy: (for thermocouples acc. to DIN EN 60584) ±1digit
(at nominal temperature ± 5K)
Type J, K, N, T, E: ± (0.5°C. + 0.2% of measured value)
Type S, B: ± (0.8°C. + 0.4% of measured value)
Temperature drift: 0.01%/K
Point of comparison: ± 0.3°C
Nominal temperature: 25°C
Measuring rate: 4 meas./sec
Sensor connection: 2 connection sockets for miniature DIN-plug type K

H76.0.02.6C-04 Operating Manual GMH 3251 page 18 of 18
_____________________________________________________ _____________________________________________________________________________
Display: Two 4½ digit LCDs (12.4 mm high and 7 mm high) for
measuring values, and for min/ max memories, hold function,
etc. as well as additional functional arrows.
Pushbuttons: 6 membrane keys
Logger: 2 functions: individual value logger („Func–Stor“) and cyclic
logger („Func–CYCL“)
Memory: Stor: 1000 data sets
CYCL: 10000 data sets (in max. 64 recording sequences)
Cycle time: 1...3600 seconds
Output: 3.5 mm audio plug, stereo,
max. permissible connection cable length: 3 m
Output function: serial interface
Interface: Serial interface (3.5 mm jack) can be connected to USB or
RS232 interface of a PC via electrically isolated interface
adapter USB3100, USB 3100 N, GRS3100 or GRS3105 (see
accessories).
Analog output: 0 ... 1 Volt, freely scaleable (resolution 12 bit)
Power supply: 9V battery (included in scope of supply)
as well as additional d.c. connector (diameter of internal pin
1.9 mm) for external 10.5-12V direct voltage supply.
(suitable power supply: GNG10/3000)
Power consumption: approx. 1.2 mA (Output „out“ = off)
approx. 1.3 mA (Output „out“ = ser)
approx. 1.6 mA (Output „out“ = dac)
Low battery warning: ' bAt '
Working conditions: -25 ... +50 °C, 0 ... 95 %RH (not condensing)
Storage temperature: -25 ... +70 °C
Housing: impact-resistant ABS, membrane keyboard, transparent panel,
Front side IP65
Dimensions: 142 x 71 x 26 mm (L x W x D)
Weight: approx. 155 g
EMC: The instruments confirm to following European Directives:
2014/30/EU EMC Directive
2011/65/EU RoHS
Applied harmonized standards:
EN 61326-1 : 2013 emissions level: class B
emi immunity according to table 3 and A.1
Additional fault: <1%
EN 50581 : 2012