Ahlborn ALMEMO 2450-1L User manual

____________________________
Operating instructions
Universal measuring instrument
ALMEMO® 2450-1L
V2.2
11.05.2010
www.ahlborn.com

1. Operating controls
1. OPE ATING CONT OLS
(1) Measuring inputs M0
M0 for a wide range of sensors
M10 to M30 3 additional channels
(2) LCD
Function field
(a) F nction
(b) Meas ring point, 2nd meas. val e
(c) Units for 2nd meas red val e
Main field
(c) Units for 1st meas red val e
(e) 1st meas red val e
(f) Operating states :
LOBAT Battery voltage <3.8 V
REL Relative meas ring
(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. val e
cancel: press and hold down
MEM Meas red val e memory
CLR Relative meas ring
Adj st sensor,
cancel: press and hold down
To switch ON with press keys :
CLR Reinitialization
MEM Device config ration
M▲ Softwareversion
Rear of device
(4) Battery compartment
3 AA alkaline-manganese batteries
2 ALMEMO® 2450-1L

Contents
2. CONTENTS
1. OPE ATING CONT OLS .........................................................................2
3. GENE AL .................................................................................................. 5
3.1 Warranty .............................................................................................. 5
3.2 Scope of delivery ................................................................................6
3.3 Waste disposal....................................................................................6
4. SAFETY INST UCTIONS..........................................................................7
4.1 Special notes on use...........................................................................8
4.2 Handling batteries / rechargeable batteries correctly......................8
5. INT ODUCTION ........................................................................................9
5.1 Functions............................................................................................. 9
5.1.1 Sensor programming ...................................................................9
5.1.2 Meas ring operations ................................................................10
6. INITIAL COMMISSIONING ......................................................................11
7. POWE SUPPLY ....................................................................................11
7.1 Battery operation and supply voltage monitoring .........................11
7.2 Sensor supply ...................................................................................11
7.3 Switching ON / OFF, reinitialization ................................................12
7.4 Data buffering ...................................................................................12
8. CONNECTING THE T ANSDUCE S .....................................................12
8.1 Transducers.......................................................................................12
8.2 Measuring inputs and additional channels ....................................13
9. DISPLAY AND KEYPAD .........................................................................14
9.1 Display ...............................................................................................14
9.2 Keypad ..............................................................................................15
10. MEASU ING OPE ATIONS ...................................................................16
10.1 Measured value...............................................................................16
10.1.1 Selecting a meas ring point ....................................................16
10.1.2 Meas ring ranges ....................................................................17
10.1.3 Do ble display..........................................................................18
10.2 Peak value memory ........................................................................18
10.3 Measured value memory ................................................................18
10.4 elative measuring ........................................................................19
11. DEVICE CONFIGU ATION .....................................................................19
11.1 Automatic switch OFF ....................................................................20
11.2 Device locking ................................................................................20
12. T OUBLE-SHOOTING ...........................................................................20
13. DECLA ATION OF CONFO MITY.........................................................21
ALMEMO® 2450-1L 3

2. Contents
14. APPENDIX ...............................................................................................22
14.1 Technical data ................................................................................22
14.2 Product overview ...........................................................................22
14.3 Index................................................................................................. 23
14.4 Your contact....................................................................................24
4 ALMEMO® 2450-1L

General
3. GENE AL
Congrat lations on yo r p rchase of this new and innovative ALMEMO®
meas ring instr ment. Thanks to the patented ALMEMO® connector the
device config res itself a tomatically; its operation sho ld be fairly straight-
forward. The device can, however, be sed with s ch a wide range of
sensors and peripherals and offers many different special f nctions. Yo are
advised therefore to properly familiarize yo rself with the way the sensors
f nction and with the device's n mero s possibilities and take the time to
caref lly read these operating instr ctions and the appropriate sections in the
ALMEMO® Man al. This is absol tely necessary to avoid operating and
meas ring errors and to prevent damage to the device. To help yo find the
answers to yo r q estions q ickly and easily there is a comprehensive index
at the end both of these instr ctions and of the Man al.
3.1 Warranty
Each and every device, before leaving o r factory, ndergoes n mero s q al-
ity tests. We provide a g arantee, lasting two years from delivery date, that
yo r device will f nction tro ble-free. Before yo send yo r device to s, please
observe the advisory notes in Chapter 12. Tro ble-shooting In the nlikely
event that the device proves defective and yo need to ret rn it please
wherever possible se the original packaging material for dispatch and enclose
a clear and informative description of the fa lt and of the conditions in which it
occ rs.
This g arantee will not apply in the following cases :
The c stomer attempts any form of na thorized tampering or alteration in-
side the device.
The device is sed in environments and conditions for which it is not s ited.
The device is sed with ns itable power s pply eq ipment and / or peri-
pherals.
The device is sed for any p rpose other than that for which it is intended.
The device is damaged by electrostatic discharge or lightning.
The ser fails to observe and comply with the operating instr ctions.
The man fact rer reserves the right to change the prod ct's characteristics in
the light of technical progress or to benefit from the introd ction of new com-
ponents.
ALMEMO® 2450-1L 5

3. General
3.2 Scope of delivery
When yo npack the device check caref lly for any signs of transport damage
and ens re that delivery is complete.
Meas ring instr ment ALMEMO® 2450-1L with 3 AA alkaline batteries
These operating instr ctions
ALMEMO® Man al
CD with the AMR-Control software and vario s sef l accessories
In the event of transport damage please retain the packaging material and in-
form yo r s pplier immediately.
3.3 Waste disposal
The pictogram showing a waste bin crossed thro gh
means that the prod ct is s bject to E ropean Union reg -
lations on segregated waste disposal. This applies both to
the prod ct itself and to any accessories marked with the
same symbol. Disposal of any s ch item as nsorted do-
mestic waste is strictly forbidden
•Please dispose of all packaging materials according to the applicable national
waste management reg lations.
•Please dispose of cardboard boxes, protective plastic packaging materials,
and all preservative s bstances separately and in the proper manner.
•The disposal of the device itself (also of device parts, accessories, and con-
s mables) is s bject to the applicable national and local waste management
reg lations and to the environmental protection legislation in force in the
co ntry of se.
•Please dispose of all waste in the proper manner;
this applies in partic lar to all parts and s bstances that constit te a hazard
for the environment. This incl des inter alia plastics, batteries, and re-
chargeable battery packs .
•When disposing of goods, please wherever possible se the original pack-
aging materials.
6 ALMEMO® 2450-1L

Safety instr ctions
4. SAFETY INST UCTIONS
DANGE Danger to life and limb, risk of damage to equipment
ead the instructions carefully before starting to operate
the device.
Please ensure that you comply with all general safety ad-
vice and the special safety instructions included in other
chapters.
S ch risks may occ r in the following circ mstances :
•Fail re to heed the operating instr ctions and all the
safety notes these contain
•Any form of na thorized tampering or alteration in-
side the device
•Use of the device in environments or conditions for
which it is not s ited
•Use of the device with an ns itable power s pply
and / or in conj nction with ns itable peripheral
eq ipment
•Use of the device for any p rpose other than that for
which it is intended
•Damage ca sed by electrostatic discharge or light-
ning.
DANGE isk of fatal injury caused by dangerously high voltage
S ch risks may occ r in the following circ mstances :
•Use of the device with an ns itable power s pply and
/ or in conj nction with ns itable peripheral eq ip-
ment
•Damage ca sed by electrostatic discharge or lightning
•Do not r n sensor lines in the vicinity of high-voltage
power cables.
•Before yo to ch any sensor lines, ens re that all stat-
ic electricity has been discharged.
ALMEMO® 2450-1L 7

4. Safety instr ctions
DANGE Warning - explosive atmospheres or substances
In the vicinity of vario s f els or chemicals there is a risk of ex-
plosion.
Do not se the device in the close vicinity of blasting work or
filling stations!
4.1 Special notes on use
•If the device is bro ght into the work-room from a cold environment
there is a risk that condensation might form on the electronics. In
meas ring operations involving thermoco ples prono nced changes in
temperat re may ca se s bstantial meas ring errors. Yo are ad-
vised therefore to wait ntil the device has adj sted to the ambient
temperat re before starting to se it.
•Before sing the mains adapter make s re that the mains voltage is
s itable.
•Be s re to observe the maxim m load capacity of the sensor power
s pply.
•Sensors with their own integrated power s pply are not electrically isol-
ated from one another
4.2 Handling batteries / rechargeable batteries correctly
When inserting batteries / rechargeable batteries ens re 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 leaking onto the device and dam-
aging it.
Rechargeable batteries sho ld be recharged as and when ne-
cessary.
Yo sho ld never attempt to recharge an ordinary (non-re-
chargeable) battery; it may explode !
Batteries / rechargeable batteries m st never be short-circ ited
or thrown onto the fire.
Batteries / rechargeable batteries are special waste and m st
not be discarded together with normal domestic waste.
8 ALMEMO® 2450-1L

Introd ction
5. INT ODUCTION
The ALMEMO® 2450-1L is a new member in o r family of niq e meas ring
devices - all eq ipped with Ahlborn's patented ALMEMO® connector system.
The intelligent ALMEMO® connector offers decisive advantages when connect-
ing sensors and peripherals beca se all parameters are stored in an EEPROM
located on the connector itself; repeat programming is th s no longer neces-
sary.
All sensors can be connected to all ALMEMO® meas ring instr ments in the
same way. Programming and f nctioning are identical for all nits. The follow-
ing points apply to all devices in the ALMEMO® meas ring system; these are
described in detail in the ALMEMO® Man al which is incl ded in delivery with
each device.
Detailed explanation of the ALMEMO® system (Man al Ch 1)
Overview of the device f nctions and meas ring ranges (Man al Ch 2)
Basic principles, operation, and technical data for all sensors (Man al Ch 3)
Options for connecting yo r own existing sensors (Man al Ch 4)
The operating instr ctions yo are now reading cover only those feat res and
controls that are specific to this device. Many sections therefore also refer to
the more detailed description in the Man al; (see Man al, Section xxx).
5.1 Functions
The ALMEMO® 2450-1L meas ring instr ment has j st one meas ring inp t
s itable for most ALMEMO® sensors - with the single exception of resistance
sensors. The meas ring possibilities are n mero s; there are 4 channels in the
sensor connectors with over 40 meas ring ranges. For operation p rposes the
device incorporates a large LCD display and a keypad.
5.1.1 Sensor programming
The meas ring channels are programmed, completely and a tomatically, by
the ALMEMO® connectors. The ser can s pplement or modify this program-
ming; this applies to the other devices only. However, this device also behave
according to all the programmed parameters.
Measuring ranges
Appropriate meas ring ranges are available for all sensors with a non-linear
characteristic, e.g. 7 thermoco ple types, NTC probes, and flow transd cers
(rotating vanes, thermoanemometers). For h midity sensors additional f nction
channels are available for calc lating h midity variables s ch as dew point,
mixt re ratio, vapor press re, and enthalpy. Meas red val es from other
sensors can also be acq ired sing the voltage and c rrent ranges with indi-
vid al scaling in the connector. Existing sensors can also be sed - so long as
the appropriate ALMEMO® connector is connected via its screw terminals. For
digital inp t signals, freq encies, and p lses, adapter connectors are available
with an integrated microcontroller. It is th s possible to connect n mero s
ALMEMO® 2450-1L 9

5. Introd ction
sensor types to any ALMEMO® meas ring instr ment and to change sensors
witho t the need for any extra settings.
Units
The 2-character nits display can be adapted for each meas ring channel so
that both the display and the printo t always indicate the correct nits, e.g.
when a transmitter is connected. Conversion between °C (Centigrade) and °F
(Fahrenheit) is performed a tomatically.
Measured value designation
Each sensor is identified by means of a 10-character alphan meric name. This
name is entered via the interface and will appear in the printo t or on the com-
p ter display.
Correction of measured values
The meas red val e on each meas ring channel can be corrected both in
terms of zero-point and gain; this means that even sensors s ally req iring
initial adj stment (e.g. expansion, force) can be freely interchanged. Sensors
with m lti-point calibration can also be connected; (see Man al Section
6.3.13).
Scaling
The corrected meas red val e on each meas ring channel can also be f rther
scaled in terms of zero-point and gain - sing the base val e and factor. The
decimal point position can be set by means of the exponent f nction.
Sensor locking
All sensor data stored in the connector EEPROM can be protected by means
of a grad ated locking f nction against ndesired access.
5.1.2 Measuring operations
A total of p to 4 meas ring channels are available for 1 transd cer; i.e. it is
also possible to eval ate do ble sensors, individ ally scaled sensors, and
sensors with f nction channels. Yo can move forwards or backwards from
one meas ring channel to the next sing the keypad. The selected meas ring
point is by defa lt assigned preferred stat s and is scanned at half the meas r-
ing rate; all other active channels are also scanned b t in the backgro nd
(semi-contin o s mode). The data is o tp t on the display.
Measured values
The meas red val e for the selected meas ring point is shown contin o sly
with a tozero and, as and when necessary, with meas red val e correction.
With most sensors, sensor breakage is detected a tomatically (except for con-
nectors with sh nt, dividers, or additional electronics).
Measuring functions
With some sensors, to achieve optimal meas red val e acq isition, certain
special meas ring f nctions are req ired. These incl de e.g. cold j nction
compensation for thermoco ples and temperat re and atmospheric press re
compensation for certain h midity variables.
10 ALMEMO® 2450-1L

F nctions
Maximum and minimum values
For each meas ring operation the maxim m val e and minim m val e are ac-
q ired and saved to memory. These val es can then be displayed, o tp t, or
deleted from memory.
Measured value memory
A meas red val e in the display can be saved by simply pressing a key.
6. INITIAL COMMISSIONING
1. Connect sensor to socket M0 (1); see 8
2. Ensure that the power supply is provided by 3 AA batteries;
3. To switch ON press key ON (3); see 7 3
4. Select measuring channels by pressing key M▲ (3), read o t meas red
val es (5e); see 10 1 1
5. Save the measured value by pressing key MEM (3); see 10 3
6. elative measuring to a reference val e by pressing key CLR (3)
Revert to normal meas red val e by pressing and holding down key CLR
7. Evaluating a measuring operation
Call p maxim m / minim m val es by pressing keys MAX / MIN (3)
To delete max. / min. val e(s) press and hold down key MAX or MIN see
10 2
7. POWE SUPPLY
Power can be s pplied to the meas ring instr ment with 3 AA alkaline batter-
ies (incl ded in delivery)
7.1 Battery operation and supply voltage monitoring
Power is s pplied to the meas ring instr ment as delivered by 3 AA batteries.
At a c rrent cons mption of approx. 10 mA the operating time will be approx.
250 ho rs. The c rrent operating voltage is displayed each time the the device
is switched on; this gives yo a basis for estimating the remaining operating
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 nscrew the
battery compartment cover (7) on the rear of the device.
7.2 Sensor supply
At the terminals + (pl s) and – (min s) in the ALMEMO® connector there is a 9-
volt sensor s pply voltage available (maxim m 150 mA) (self-healing f se, 500
mA). Other voltages (12, 15, or 24 V or references for a potentiometer and
strain ga ge) can be obtained sing special connectors; (see Manual 4 2 5 and
4 2 6).
ALMEMO® 2450-1L 11

7. Power s pply
7.3 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 OFFr. After the device is switched off all saved val es and settings are re-
tained intact; (see 7.4).
If interference (e.g. electrostatic) or a malf nction (e.g. battery fail re) ca ses
the device to behave abnormally, the device can be reinitialized. To activate
ESET press and hold down the key CLR r when switching on. This will restore
all settings to the factory defa lt stat s. Only the programming of the sensors
in the ALMEMO® connectors remains naffected.
7.4 Data buffering
The sensor's programming is stored in the EEPROM on the sensor connector
and the device's calibration and programmed parameters are stored in the EE-
PROM on the instr ment itself, both on a fail-safe basis.
8. CONNECTING THE T ANSDUCE S
Only certain ALMEMO® sensors can be connected to ALMEMO® inp t socket
M0 (1), namely those programmed with meas ring ranges as per Ch 10.1.2.
Attempting to connect any other sensor here will trigger an error message. To
connect yo r own existing sensors yo simply need the appropriate AL-
MEMO® connector.
8.1 Transducers
The ALMEMO® Man al incl des detailed descriptions of the ALMEMO® range
of sensors (see Man al Ch 3) and instr ctions for connecting yo r own existing
sensors to ALMEMO® instr ments (see Man al Ch 4). All s itable sensors with
an ALMEMO® connector (see above) have the meas ring range and nits
already programmed and can th s be connected to the inp t socket witho t
f rther adj stment. A mechanical coding system ens res that sensors and o t-
p t mod les can only be connected to the correct sockets. All ALMEMO® con-
nectors incorporate two snap-lock levers; these snap into position as soon as
the connector is inserted into the socket, th s preventing nintended discon-
nection if the cable is accidentally p lled. To withdraw the connector, both
these levers m st be pressed in at the sides.
For the ALMEMO® 2450-1L version with the optional seal new specially de-
signed sensors are available with spray-coated ALMEMO® connectors incor-
porating a do ble sealing lip to protect the socket nit against the effects of
splashing water. For any n sed sockets protective stoppers are available.
12 ALMEMO® 2450-1L

Meas ring inp ts and additional channels
8.2 Measuring inputs and additional channels
The ALMEMO® 2450-1L meas ring instr ment has one inp t socket (1) to
which initially meas ring channel M0 is assigned. ALMEMO® sensors can,
however, if necessary, provide p to fo r channels. The additional channels
can be sed in partic lar for h midity sensors with fo r meas ring variables
(temperat re / h midity / dew point / mixt re ratio) or for f nction channels.
Each sensor can if necessary be programmed with several meas ring ranges
or scaling settings; and two or three sensors, if pin assignment so permits, can
be combined in a single connector (e.g. rH / NTC, mV / V, mA / V, etc.). The
additional meas ring channel n mbers per connector go p in steps of 10 (e.g.
the first sensor has channels M0, M10, M20, M30).
Do ble connectors with 2 x differential voltage / differential c rrent
(inp t D - B) are not possible.
On the meas ring instr ment this gives the following channel assignment :
Sensors combined within one connector and sensors with their own power
s pply are electrically interconnected and m st therefore be operated in isola-
tion. The voltage at the meas ring inp ts themselves m st not exceed 5 volts
(between B, C, D, A and - ).
ALMEMO® 2450-1L 13
M0
00
10
20
30
1. chan.
2. chan.
3. chan.
4. chan.
A2 A1 DC
sensor channels
P0


9. Display and keypad
9. DISPLAY AND KEYPAD
9.1 Display
The display (2) on the ALMEMO® 2450-1L meas ring instr ment is a 2-row
LCD arrangement; the main field comprises 5x 7-segment digits (e) pl s 2x 16-
segment digits (d) for depicting the meas red val e;,the f nction field com-
prises 41/2x 7-segment digits (b) for depicting vario s meas ring f nctions (a);
there are also 2 arrows (f) for depicting the operating stat s.
F nction field
Main field
Display of measuring functions in the f nction field
Meas ring point
Maxim m val e
Minim m val e
Saved val e
Temperat re val e from do ble sensors
Config ration of locking
Config ration of a tomatic OFF
14 ALMEMO® 2450-1L
MAX 36.5
MIN 17.3
M 36.2
M O
26.5 °C
Loc
AOFF

Display
Special operating states and faults
Display segment test : r ns a tomatically after switch ON
S pply voltage Display after segment test
Under 3.8 V : LOBAT arrow lights p
Relative meas ring with respect to a reference val e : REL arrow lights p
Checks m error in
device calibration :
Non-connected sensors,
deactivated meas ring points :
Meas ring range / f nction not permitted :
M ltiplexer M5 (D-B) is not allowed:
Sensor breakage : flashes
O tside of meas ring range, ndershoots
cold j nction compensation flashes
or cold j nction compensation breakage :
Overshoots val es range (>65000) : flashes
Overshoots meas ring range : Maxim m val e flashes
Undershoots meas ring range : Minim m val e flashes
9.2 Keypad
To operate the device a keypad with 7
keys is provided :
Function :
Key
To switch ON the device : (see Section 7.3) ON OFF
To switch OFF the device : ON OFF
must be pressed and held down
Function : Key
Selection of meas ring points (see Section 10.1.1) M ▲ or M ▼
ALMEMO® 2450-1L 15
CALEr
-----
Err
NiCr
CJ
65OOO
ErrI

9. Display and keypad
Displaying the maxim m val e : (see Section 10.2) MAX
To delete press and hold down
Displaying the minim m val e : (see Section 10.2) MIN
To delete press and hold down
Zero-setting the meas red val e : (see Section 10.4) CLR
To delete press and hold down
Saving the meas red val e : (see Section 10.3) MEM
Displaying the battery voltage : ON OFF
10. MEASU ING OPE ATIONS
On the ALMEMO® 2450-1L all meas ring channels, whenever available, are
scanned semi-contin o sly at 2.5 mops; (see Man al 6.5).
Up to 4 meas ring points can be displayed; (see Section 8.2)
10.1 Measured value
After switching ON first of all a segment test
is performed; then the battery voltage ap-
pears and if the batteries are almost empty
(<3.8 V) the LOBAT arrow also appears.
The meas red val e is then displayed with
the appropriate nits in the main field and the
meas ring point is displayed in the f nction
field. All special operating states possible for
the meas red val e are explained in Section
.
10.1.1 Selecting a measuring point
By pressing key M ▲ yo can select one after the other all active meas ring
points and have the c rrent meas red val e displayed for each. By pressing
key M ▼ yo can ret rn to the previo s channel.
To increment the meas ring channel press key : M ▲
To decrement the meas ring channel press : M ▼
When switching between channels the abbreviation for the meas ring range is
briefly displayed; (see 10.1.2).
16 ALMEMO® 2450-1L

Meas red val e
10.1.2 Measuring ranges
With each channel switchover or sensor breakage the abbreviation for the
meas ring range appears in the display. For identification p rposes the follow-
ing table lists all possible meas ring ranges s pported by this device.
Transducer Sensor / con-
nector
Measuring range Units Abbre-
viation
NiCr-Ni (K) FT Axxx -200.0...+1370.0 °C NiCr
NiCroSil-NiSil (N) ZA 9020-FSN -200.0...+1300.0 °C NiSi
Fe-C Ni (L) ZA 9000-FSL -200.0... +900.0 °C FECO
Fe-C Ni (J) ZA 9000-FSJ -200.0... +950.0 °C IrCo
C -C Ni (U) ZA 9000-FSU -200.0... +600.0 °C CUCO
C -C Ni (T) ZA 9000-FST -200.0... +400.0 °C CoCo
PtRh10-Pt (S) FS Axxx 0.0...+1760.0 °C Pt10
Ntc Typ N FN Axxx -30.00...+125.00 °C Ntc
Millivolt ZA 9000-FS0 -10.000...+55.000 mV U 55
Millivolt 1 ZA 9000-FS1 -26.000...+26.000 mV U 26
Millivolt 2 ZA 9000-FS2 -260.00...+260.00 mV U260
Volt ZA 9000-FS3 -0.2600...+2.6000 V U2.60
Difference millivolt ZA 9000-FS0D -10.000...+55.000 mV d 55
Difference millivolt 1 ZA 9000-FS1D -26.000...+26.000 mV d 26
Difference millivolt 2 ZA 9000-FS2D -260.00...+260.00 mV d260
Difference volt ZA 9000-FS3D -0.2600...+2.6000 V d2.60
Sensor voltage any 0.00...20.00 V UbAt
Milliampere ZA 9601-FS1 0.000...+26.000 mA I032
Percent (4-20mA) ZA 9601-FS2 0.00... 100.00 % P420
Freq ency ZA 9909-AK1 0... 32000 Hz FrE
Digital inp t ZA 9000-EK2 0.0... 100.0 % Inp
Digitale interface ZA 9919-AKxx -65000... +65000 diGi
Snap-on head normal 20 FV A915-S120 0.30... 20.00 m/s S120
Snap-on head normal 40 FV A915-S140 0.40... 40.00 m/s S140
Snap-on head micro 20 FV A915-S220 0.50... 20.00 m/s S220
Snap-on head micro 40 FV A915-S240 0.60... 40.00 m/s S240
Macro FV A915-MA1 0.10... 20.00 m/s L420
Water-Micro FV A915-WM1 0.00... 5.00 m/s L605
Relative air h midity, capacitive FH A646 0.0... 100.0 %H °orH
Rel. air h midity, capacitive TC FH A646-C 0.0... 100.0 %H HcrH
Rel. air h midity, capacitive TC FH A646-R 0.0... 100.0 %H H rH
Mixt re ratio, capacitive FH A646 0.0 ... 500.0 g/k H AH
Dew-point temperat re, cap. FH A646 -25.0... 100.0 °C H dt
Partial vapor press re, cap. FH A646 0.0 ...1050.0 mb H UP
Enthalpy, capacitive FH A646 0.0 ... 400.0 kJ H En
ALMEMO® 2450-1L 17

10. Meas ring operations
Transducer Sensor / con-
nector
Measuring range Units Abbre-
viation
Functions channels:
Maxim m val e of channel Mb1 any Hi
Minim m val e of channel Mb1 any Lo
Alarm val e of channel Mb1 any Alrn
Meas red val e of Mb1 any MESS
Cold j nction temperat re any °C CJ
TC=Temperat re compensation
10.1.3 Double display
On all do ble sensors incorporating a tem-
perat re sensor on the 1st channel the tem-
perat re val e can at the same time be dis-
played in the f nction field.
Select 2nd channel
Activate temperat re display Press and hold dow M▲
Ret rn to channel display Press and hold down M▲
10.2 Peak value memory
From the meas red val es acq ired for each
meas ring point the highest and the lowest
val es are contin o sly recorded. To display
these high/low peak val es first the desired
channel m st be set (see Section 7.1) and
then the MAX or MIN key m st be
pressed. As a check the display also incl des
the associated symbol.
To display the maxim m val e press key : MAX .
To display the minim m val e press key : MIN .
To delete the maxim m val e press and hold down key : MAX .
To delete the minim m val e press and hold down key : MIN .
To ret rn to the meas ring point display press key : M ▲ .
As soon as yo clear the memory, the c rrent meas red val e will appear (be-
ca se meas ring is contin o s).
10.3 Measured value memory
On the ALMEMO® 2450-1L any meas red
val e can be saved. To save the meas red
val e press key : MEM .
The val e most recently saved then appears
in the f nction field preceded by the symbol
´M´. To ret rn to the channel display press key : M ▲ .
18 ALMEMO® 2450-1L

Relative meas ring
10.4 elative measuring
One very sef l f nction is to zero the meas-
red val e at certain locations or at certain
times as a reference val e in order then to ob-
serve only the s bseq ent deviations. This
f nction is independent of the locking stat s
and does not modify the programming para-
meters in the connector.
To zero-set the meas red val e press key : CLR .
To display relative meas ring press arrow : EL.
To ret rn to normal meas red val e press and hold down key : CLR .
Setting to zero a tomatically deletes the maxim m and minim m val-
es for this channel. The MAX, MIN, and MEM f nctions are th s also
available for relative meas rement.
11. DEVICE CONFIGU ATION
On the ALMEMO® 2450 meas ring instr -
ment a n mber of parameters can be con-
fig red. To do so when switching ON press
and hold down key MEM . The f nction field
sho ld then show an abbreviation for the
parameter and the main field sho ld show
the val e c rrently set.
To select from all possible parameters,
if any are available, press keys : M ▲ or M ▼ .
Locking the CLR key: see 11.2
A tomatic switch OFF time in min tes: see 11.1
To enter a value first press : ON and the val e
starts flashing.
To modify the val e press keys : M ▲ or M ▼
To delete parameters press : CLR
Entry is completed by again pressing key : ON
To terminate configuration at any time press key: MEM
ALMEMO® 2450-1L 19

AOFF
Loc

11. Device config ration
11.1 Automatic switch OFF
In men item ´AOFF´ an a tomatic device switch OFF time can be programmed
in min tes; this will help save the batteries. This a tomatic device switch OFF
will not take effect if the setting is ´- -´ or if a mains adapter or an interface
cable is connected.
11.2 Device locking
The meas red val e in the main field of the display can be manip lated by
pressing key CLR and setting it to zero. This f nction can be eval ated in dif-
ferent ways or even switched off in cases where there is a risk of accidentally
activating relative meas ring by zero-setting the meas red val e.
Loc parameter :
0 The offset is saved in RAM, base or zero-point - depending on locking
1 The offset is saved in RAM only.
2 Relative meas ring is locked
12. T OUBLE-SHOOTING
The ALMEMO® 2450-1L meas ring instr ment can be config red and pro-
grammed in many versatile ways. It is s itable for connecting a wide variety of
different sensors. Given these n mero s possibilities the device may in certain
circ mstances not behave q ite as expected. The ca se of s ch nexpected
behavior is only very rarely a device defect; more s ally it is incorrect opera-
tion by the ser, an invalid setting, or ns itable cabling. In s ch event try to
pinpoint and clear the problem with the aid of the following tests.
Error: No display, display malf nction, keys do not react
emedy: Check the power s pply; replace the batteries; switch off and then
on again; if necessary re-initialize (see 7.3).
Error: Meas red val es are incorrect.
emedy: Switch Device OFF / ON, press key and hold CLR . Check all the
sensor programming very caref lly, especially the base val e and
zero-point.
Error: Fl ct ating meas red val es or the system hangs in mid-operation.
emedy: Check the cabling for any inadmissible electrical connections,
Unpl g any s spicio s sensors.
Connect hand-held sensors in air or phantoms (for thermoco ples short-cir-
c it AB) and check.
Connect the sensors again one at a time and check s ccessively.
If a fa lt persists for any one connection, then check all wiring; if necessary,
ins late the sensor and eliminate interference by sing shielded or
twisted wiring.
Error: ´CALEr´is displayed when the device is switched on.
emedy: The calibration of a meas ring range may have become misadj s-
20 ALMEMO® 2450-1L