Ahlborn THERM 2420 User manual

____________________________
Operating instructions
Temperature measuring instrument
THERM 2420
V1.2
27.11.2007
www.ahlborn.com

1. Operating controls
1. OPERATING CONTRO S
(1) Measuring input M
M for temperature sensors with
miniature thermal connector
(2) CD
Function field
(a) Function
(b) Function value
Main field
(c) nits
(d) Measured value
(e) Operational status
LOBAT Battery voltage <3.8 V
REL Relative measuring
(3) Operating keys
ON OFF Switch the device on
To switch device OFF, press and hold down
M▲ , M▼ Meas. point selection
MAX , MIN Max. / min. value
clear: press and hold down
MEM Measured value memory
CLR Relative measuring,
Adjust sensor,
cancel: press and hold down
To switch ON with press keys :
CLR Reinitialization
MEM Device configuration
M▲ Softwareversion
Rear of device
(4) Battery compartment
3 AA alkaline-manganese batteries
2 THERM 2420

Contents
2. CONTENTS
1. OPERATING CONTRO S .........................................................................2
3. GENERA ..................................................................................................4
3.1 Warranty ..............................................................................................4
3.2 Scope of delivery ................................................................................4
3.3 Handling batteries / rechargeable batteries correctly .....................5
3.4 Special notes on use ..........................................................................5
4. INTRODUCTION ........................................................................................5
5. INITIA COMMISSIONING ........................................................................6
6. POWER SUPP Y ......................................................................................6
6.1 Battery operation and supply voltage monitoring ...........................6
6.2 Switching ON / OFF, reinitialization ..................................................6
7. CONNECTING THE TRANSDUCERS .......................................................6
8. DISP AY AND KEYPAD ...........................................................................7
8.1 Display .................................................................................................7
8.2 Keypad ................................................................................................8
9. MEASURING OPERATIONS .....................................................................9
9.1 Measured value...................................................................................9
9.2 Measured value functions..................................................................9
9.3 Peak value memory ..........................................................................10
9.4 Measured value memory ..................................................................10
9.5 Relative measuring ..........................................................................10
10. DEVICE CONFIGURATION .....................................................................11
10.1 Measuring ranges ...........................................................................11
10.2 Automatic switch OFF ....................................................................11
10.3 Function locking .............................................................................12
11. TROUB E-SHOOTING ...........................................................................12
12. E ECTROMAGNETIC COMPATIBI ITY (EMC) .....................................13
13. APPENDIX ...............................................................................................14
13.1 Technical data ................................................................................14
13.2 Product overview ...........................................................................14
13.3 Index.................................................................................................15
13.4 Your contact....................................................................................16
THERM 2420 3

3. General
3. GENERA
Congratulations on your purchase of this AHLBORN temperature measuring
instrument for thermocouple sensors with a miniature thermal connector. You
are strongly advised to properly familiarize yourself with the device's numerous
possibilities and take the time to carefully read these operating instructions.
This is absolutely necessary to avoid operating and measuring errors and to
prevent damage to the device. To help you find the answers to your questions
quickly and easily there is a comprehensive index at the end these instruc-
tions.
3.1 Warranty
Each and every device, before leaving our factory, undergoes numerous quali-
ty tests. We provide a guarantee, lasting two years from delivery date, that your
device will function trouble-free. Before you send your device to us, please ob-
serve the advisory notes in Chapter 11 Trouble-shooting. In the unlikely event
that the device proves defective and you need to return it please wherever pos-
sible use the original packaging material for dispatch and enclose a clear and
informative description of the fault and of the conditions in which it occurs.
This guarantee will not apply in the following cases :
The customer attempts any form of unauthorized tampering or alteration in-
side the device.
The device is used in environments and conditions for which it is not suited.
The device is used with an unsuitable power supply.
The device is used for any purpose other than that for which it is intended.
The device is damaged by electrostatic discharge or lightning.
The user fails to observe and comply with the operating instructions.
The manufacturer reserves the right to change the product's characteristics in
the light of technical progress or to benefit from the introduction of new compo-
nents.
3.2 Scope of delivery
When you unpack the device check carefully for any signs of transport damage
and ensure that delivery is complete.
Measuring instrument THERM 2420 with 3 AA alkaline batteries
These operating instructions
In the event of transport damage please retain the packaging material and in-
form your supplier immediately.
4 THERM 2420

Handling batteries / rechargeable batteries correctly
3.3 Handling batteries / rechargeable batteries correctly
When inserting batteries / rechargeable batteries ensure that
these are correctly polarized. If the device will probably not be
needed for a relatively long period of time or if the batteries are
empty remove the batteries; this will prevent battery acid spilling
on and damaging the device. Rechargeable batteries should be
recharged as and when necessary. You should never attempt to
recharge an ordinary (non-rechargeable) battery; it may explode !
Batteries / rechargeable batteries must never be short-circuited
or thrown on the fire. Batteries / rechargeable batteries are spe-
cial waste and must not be discarded together with normal do-
mestic waste.
3.4 Special notes on use
If the device is brought into the work-room from a cold environment there is
a risk that condensation might form on the electronics. In measuring opera-
tions involving thermocouples pronounced changes in temperature may
cause substantial measuring errors. You are advised therefore to wait until
the device has adjusted to the ambient temperature before starting to use it.
Do not run sensor lines in the vicinity of high-voltage power cables.
Before you touch any sensor lines, ensure that all static electricity has been
discharged.
4. INTRODUCTION
The THERM 2420 measuring instrument has just one measuring input with a
miniature thermal socket suitable for connecting most thermocouple sensors.
For operation purposes the device incorporates a large LCD display and a key-
pad.
Functions
Measuring ranges
7 thermocouple types, units can be selected °C or °F or mV.
Measured value
Measured data acquisition at 2.5 mops, automatic cold junction compensation,
autozero, and sensor breakage detection
Relative measuring
The measured value can at any time be set to zero in order to display the dif-
ference with respect to a reference value.
Maximum and minimum values
For each measuring operation the maximum value and minimum value are ac-
quired and saved to memory. These values can be displayed and, as and
when necessary, deleted.
Measured value memory
A measured value in the display can be saved by simply pressing a key.
THERM 2420 5

5. Initial commissioning
5. INITIA COMMISSIONING
1.Connect sensor to socket M (1) see 7.
2. Ensure power supply is connected with 3 AA batteries see 6.1
3. To switch ON press key ON (3) see 6.2
4. Save the measured value by pressing key MEM (3) see 9.4
5. Relative measuring to a reference value by pressing key CLR (3).
Revert to normal measured value by pressing and holding down key CLR
6. Evaluating a measuring operation
Call up maximum / minimum values by pressing keys MAX / MIN (3).
To delete maximum / minimum value(s) press and hold down
keys MAX or MIN see 9.3
7. To switch OFF press and hold down key ON (3) see 6.2
6. POWER SUPP Y
6.1 Battery operation and supply voltage monitoring
The power supply for this device is normally provided by 3 AA alkaline batter-
ies. At a current consumption of approx. 10 mA the operating time will be ap-
prox. 250 hours. The current operating voltage is displayed each time the the
device is switched on; this gives you a basis for estimating the remaining oper-
ating time. When the remaining battery capacity drops to approx. 10 percent,
the LOBAT arrow will appear in the display. If the batteries are completely dis-
charged the device will switch off. To replace old batteries first unscrew the
battery compartment cover (4) on the rear of the device.
6.2 Switching ON / OFF, reinitialization
To switch the device ON briefly press and release the key ON OFFr (3) in the
middle of the keypad; to switch the device OFF press and hold down the key
ON OFF.
If interference (e.g. electrostatic) or a malfunction (e.g. battery failure) causes
the device to behave abnormally, the device can be reinitialized. To activate
RESET press and hold down the key CLR r when switching on. This will restore
all settings to the factory default status. The calibration data is stored in the
EEPROM on the instrument itself, on a fail-safe basis.
7. CONNECTING THE TRANSDUCERS
Input socket M on the measuring instrument (1) can be used to connect 7 dif-
ferent thermocouple sensors with a miniature thermal connector. The various
possible types and their measuring ranges are listed in Section 10.1. To con-
nect your own existing sensors you simply need the appropriate miniature ther-
mal connector, ensure that these are correctly polarized.
6 THERM 2420

Display and keypad
8. DISP AY AND KEYPAD
8.1 Display
The display (5) on the THERM 2420 measuring instrument is a 2-row LCD ar-
rangement; the main field comprises 5x 7-segment digits (d) plus 2x 16-seg-
ment digits (c) for depicting the measured value; the function field comprises
41/2x 7-segment digits (b) for depicting various measuring functions (a); there
are also 2 arrows (e) for depicting the operating status.
Function field
Main field
Display of measuring functions in the function field
Measured value with measuring range abbreviation :
Maximum value
Minimum value
Saved value
Configuration of measuring range
Configuration of automatic OFF
Configuration of function locking
THERM 2420 7
MAX 36.5
MIN 17.3
M 36.2
NiCr
AOFF
Loc
type

8. Display and keypad
Special operating states and faults
Display segment test : runs automatically after switch ON
Supply voltage Display after segment test
nder 3.8 V : LOBAT arrow lights up
Relative measuring with respect to a reference value : REL arrow lights up
Checksum error in
device calibration :
Sensor breakage : flashes
Outside of measuring range, undershoots
cold junction compensation or cold junc flashes
tion compensation breakage :
Function is locked : This appears
briefly
Overshoots measuring range : Maximum value flashes
ndershoots measuring range : Minimum value flashes
8.2 Keypad
To operate the device a keypad with 7 keys is provided :
Function : Key
To switch ON the device : (see Section 6.2) ON OFF
To switch OFF the device : ON OFF must be
pressed and held down
Selecting the units : (see Section 9.2) M▲ or M▼
Displaying the maximum value : (see Section 9.3) MAX
To delete press and hold down
Displaying the minimum value : (see Section 9.3) MIN
To delete press and hold down
Zero-setting the measured value : (see Section 9.5) CLR
To delete press and hold down
8 THERM 2420
CALEr
NiCr
CJ
Loc

Keypad
Saving the measured value : (see Section 9.4) MEM
Displaying the battery voltage : ON OFF
9. MEASURING OPERATIONS
To perform a measuring operation connect the sensor at socket M (see Chap-
ter 7). The measured value is acquired continuously at 2.5 mops.
9.1 Measured value
After switching ON first of all a segment test is
performed; then the battery voltage appears and
if the batteries are almost empty (< 3.8 V) the LO
BAT arrow also appears.
(see Section 6.1)
The battery voltage display can be repeated at
any time by pressing key ON .
In the main field you will then see the tempera-
ture value with its units; in the function field you
will see the abbreviation for the thermocouple
(see Section 10.1). All special operating states
possible for the measured value are explained in
Section 8.1.
9.2 Measured value functions
By pressing key M▲ units °C and °F can be selected one after the other and
as a check also the voltage in mV or the internal cold junction temperature, if
these functions have been enabled (see Section 10.3). The current measured
value is displayed in the main field together with the appropriate units. By
pressing key M▼ you can jump back to the previous function.
To select the measured value function press keys : M▲ , M▼
nits in °F Voltage in mV Cold junction temperature
By default changing the measured value functions is locked in the
device configuration (display ´LOC´) and must first be unlocked(see
Section 10.3).
THERM 2420 9


9. Measuring operations
9.3 Peak value memory
From the measured values acquired the high-
est and the lowest values are continuously
recorded. To display these peak values press
key MAX or MIN . As a check the display
also includes the associated symbol.
To display maximum value press key : MAX
To display minimum value press key : MIN
To delete maximum value press and hold down key : MAX
To delete minimum value press and hold down key : MIN
To jump back to the operating range display press key : M▲
As soon as you clear the memory, the current measured value will appear (be-
cause measuring is continuous).
9.4 Measured value memory
On the THERM 2420 any measured value can
be saved. To save the measured value press
key MEM The currently saved value then ap-
pears in the function field preceded by the
symbol ´M´. To jump back to the operating
range display press key : M▲
9.5 Relative measuring
One very useful function is to zero the mea-
sured value at certain locations or at certain
times as a reference value in order then to ob-
serve only the subsequent deviations.
By default this function is also locked in the de-
vice configuration (display ´LOC´) (see 10).
To zero-set the measured value press key : CLR
To display relative measuring press arrow : RE
To return to normal measured value : press and hold down CLR
Setting to zero automatically deletes the maximum and minimum val-
ues for this channel. The MAX, MIN, and MEM functions are thus also
available for relative measuring.
10 THERM 2420


Device configuration
10. DEVICE CONFIGURATION
On the THERM 2420 measuring instrument a
number of parameters can be configured. To
do so when switching ON press and hold down
key MEM . The function field should then show
an abbreviation for the parameter and the main
field should show the value currently set.
To select from all possible parameters press keys : M▲ or M▼
Measuring range
Automatic switch OFF time in minutes: see 10.2
Function locking : see 10.3
To enter a value first press : ON and the value starts
flashing.
To modify the value press keys : M▲ or M▼
Entry is completed by again pressing key : ON
To terminate configuration at any time press key : MEM
10.1 Measuring ranges
The following measuring ranges can be set via menu item ´type´.
Transducer Type Measuring range Units Abbrevi-
ation
NiCr-Ni K -200.0...+1370.0 °C NiCr
NiCroSil-NiSil N -200.0...+1300.0 °C NiSil
Fe-CuNi L -200.0... +900.0 °C FECO
Fe-CuNi J -200.0... +950.0 °C IrCo
Cu-CuNi -200.0... +600.0 °C CUCO
Cu-CuNi T -200.0... +400.0 °C CoCo
PtRh10-Pt S 0.0...+1760.0 °C Pt10
10.2 Automatic switch OFF
In menu item ´AOFF´ an automatic device switch OFF time can be programmed
in minutes; this will help save the batteries. This automatic device switch OFF
will not take effect if the setting is ´- -´.
THERM 2420 11
AOFF
type
Loc

10. Device configuration
10.3 Function locking
Since there is a risk that the measuring functions or relative measuring opera-
tions may lead to misinterpretation, these are normally locked at level 3. These
can, however, be individually enabled via menu item ´Loc´ :
Loc parameter ocked functions
0 None
1 Measuring functions (the previously selected function is retained)
2 Relative measuring
3 Measuring functions and relative measuring (default)
11. TROUB E-SHOOTING
The THERM 2420 measuring instrument can be configured. If in certain cir-
cumstances the device does not respond exactly as it should, the cause of
such unexpected behavior is only very rarely a device defect; more usually it is
incorrect operation by the user, an invalid setting, or unsuitable cabling. In such
event try to pinpoint and clear the problem with the aid of the following tests.
Error: No display, display malfunction, keys do not react
Remedy: Check the power supply, charge the battery, switch off and then on
again. If necessary, re-initialize; (see 6.2).
Error: Measuring functions or relative measuring cannot be started.
Remedy: Check device configuration; see 10, 10.3
Error: Measured values are incorrect.
Remedy: Switch Device OFF / ON, press key and hold CLR . Check measur-
ing range configuration; see 10
Error: Fluctuating measured values or the system hangs in mid-operation.
Remedy: Check connecting cable(s), connect hand-held sensors in air or
phantoms (for thermocouples short-circuit) and check.
Then reconnect the sensor and check; if necessary, insulate the sen-
sor and eliminate interference by using shielded or twisted wiring.
Error: ´CALEr´ is displayed when the device is switched on.
Remedy: The calibration of a measuring range may have become misadjust-
ed. The device must be recalibrated at the factory.
If, after performing the above-listed checks and remedial steps, the device still
fails to behave as described in the operating instructions, it must be returned to
our factory in Holzkirchen, accompanied by an explanatory note and error de-
scription.
12 THERM 2420

Electromagnetic compatibility (EMC)
12. E ECTROMAGNETIC COMPATIBI ITY (EMC)
The THERM 2420 measuring instrument complies in full with the safety re-
quirements specified in the E directive relating to electromagnetic compatibili-
ty (EMC) (89/336/EWG).
The following standards have been applied in evaluating the product.
IEC 61326:1997+A1:1998+A2:2000
IEC 61000-6-1:1997 IEC 61000-4-2: 1995+A1:1998+A2:2000 8kV
IEC 61000-6-3:1996 IEC 61000-4-4: 1995+A1:2000 2kV
IEC 61000-4-3: 1995+A1:1998+A2:2000 3V/m
The following advisory notes must be observed when operating the device.
1. If the standard sensor is extended (1.5 meters) care must be taken to ensure that
the measuring lines are not laid together with high-voltage power cables and that,
if necessary, they are properly shielded so as to prevent spurious interference be-
ing induced in the system.
2. sing the device in strong electromagnetic fields may aggravate measuring errors
(<50 µV at 3 V/m and 1.5 meters thermocouple sensor). After exposure to such ir-
radiation ceases, the device will again operate within its technical specifications.
THERM 2420 13

13. Appendix
13. APPENDIX
13.1 Technical data
Measuring input : 1 miniature thermal socket for thermocouples with
miniature thermal flat connector
A/D converter : Delta-sigma 15-bit, at measuring rate 2.5 mops
Gain : 40, 80
Common mode input range : -0.26 ... +2.6 V, Overload max. -4..+5V
Input current : < 2 nA
System accuracy : ± 0.1 % v. Measuring values ± 3 Digit
Temperature drift : 0.01 %/°C
Cold junction compensation: -30 ... +100 °C, Accuracy : ± 0.2 K ± 0.01K/°C
Self-calibration: Automatic zero point correction
Control functions: automatic sensor failure detection
Measuring ranges
NiCr-Ni Type K -200.0...+1370.0 °C
NiCroSil-NiSil Type N -200.0...+1300.0 °C
Fe-CuNi Type L -200.0... +900.0 °C
Fe-CuNi Type J -200.0... +950.0 °C
Cu-CuNi Type -200.0... +600.0 °C
Cu-CuNi Type T -200.0... +400.0 °C
PtRh10-Pt Type S 0.0...+1760.0 °C
Millivolt -10.000...+55.000 m
Standard equipment
LCD : Measured value : 5x 7-segment 15 mm,
2x 16-segment 9 mm
Function 4½ x 7-segment 9 mm, 5 symbols
Operation : 7 silicone keys
Memory : 1 measuring value on the RAM
Microprocessor : M16C28
Power supply :
Batteries : 3 AA alkaline batteries
Current consumption : approx. 10 mA
Battery operating time : approx. 250 hours
Housing : (LxWxH) 127 x 83 x 42 mm ABS (acrylonitrile butadi-
ene styrene), weight : approx. 260 g
Suitable conditions
Operating temperature -10 to +60 °C
(storage temperature -20 to +60 °C)
Ambient relative humidity : 10 to 90 % rH (non-condensing)
13.2 Product overview
Temperature measuring instrument THERM 2420 Order no.
1 measuring input , 2-row LCD, 7 keys, 3 AA batteries MT 24201L
14 THERM 2420
(see Manual 2.3)

Index
13.3 Index
Automatic switch OFF 10.2 11
Battery operation 6.1 6
battery voltage display 9.1 9
configuration 10 11
Connecting the transducers 7 6
Device configuration 10 11
Display 8 7
Electromagnetic compatibility (EMC) 12 13
function field 8.1 7
Function locking 10.3 12
Housing 13.1 14
Initial commissioning 5 6
Introduction 4 5
keypad 8 7
Keypad 8.2 8
maximum value 9.3 10
Measured value 9.1 9
Measured value functions 9.2 9
Measured value memory 9.4 10
Measuring input 13.1 14
Measuring operations 9 9
Measuring ranges 10.1 11
Order no. 13.2 14
Peak value memory 9.3 10
Power supply 13.1 6, 14
Product overview 13.2 14
reference value 9.5 10
reinitialization 6.2 6
Relative measuring 9.5 10
Scope of delivery 3.2 4
Suitable conditions 13.1 14
supply voltage monitoring 6.1 6
Switching ON / OFF 6.2 6
Technical data 13.1 14
To switch OFF 8.2 8
To switch ON 8.2 8
Trouble-shooting 11 12
Warranty 3.1 4
THERM 2420 15

13. Appendix
13.4 Your contact
16 THERM 2420