Ahlborn ALMEMO D7 User manual

www.ahlborn.com
Operating instructions
V7 ALMEMO® D7 digital sensors
Measuring connector ±64 mV, ±250 mV, ±2 V, ±20 V, 20 mA ZED700/1/2-F (2)
Pt100 connector ZPD70x-F
Potentiometer connector ZWD700-F
Bridge connector ZKD700-F
Tensile and compressive force sensors FK0xx+ ZKD712-F
Precision pressure transducer FD8214xx+ ZDD714-AK
Pressure transducer FD0602Lxx+ ZDD702-AKL
Conductivity sensor FYD741-LF
Meteo Multi sensor FMD760
GP transducer FGD701
D7 thermocouple plug ZTD700-F
D7-Pt1000-plug ZPD710-F
V2.15
28.08.2017

ALMEMO® D7 digital sensors
1. Operation as sensor on ALMEMO® V7 measuring instruments. .4
1.1. Atmospheric pressure measurement and compensation..................................4
1.2. Correction of measured values........................................................................5
1.3. ensor menu....................................................................................................5
1.4. Configuration on PC via U B adapter cable...................................................5
2. D7 UI connectors ZED700 FS, ZED701 FS, ZED702 FS..............7
2.1. Pin assignment.................................................................................................7
3. D7 Pt100 connector ZPD70x FS......................................................8
3.1. Pin assignment.................................................................................................8
4. D7 Potentiometer connector ZWD700 FS......................................9
4.1. Pin assignment.................................................................................................9
5. D7 bridge connector ZKD700 FS..................................................10
5.1. Configuration via the sensor menu................................................................10
5.2. ensor adjustment and scaling.......................................................................11
5.3. Pin assignment...............................................................................................11
6. D7 tensile and compressive force sensors FK0xx.........................12
6.1. Configuration via the sensor menu................................................................12
6.2. ensor functions............................................................................................12
6.3. Technical data ZKD712-F ...........................................................................13
7. D7 pressure sensors FD0602Lxx....................................................13
7.1. Technical data ZDD702AKLxx....................................................................13
7.2. D7 pressure sensors FD8214xx.....................................................................13
7.3. Technical data ZDD714AKxx.......................................................................13
8. D7 conductivity probe FYD741LF................................................14
8.1. Basic principles..............................................................................................14
8.2. Measuring principle.......................................................................................15
8.3. Configuration via the sensor menu................................................................15
8.3.1. Configurable measuring quantities and ranges.............................................15
8.3.2. Cell constant..................................................................................................16
8.3.3. etpoint..........................................................................................................16
8.3.4. Temperature compensation...........................................................................16
8.4. Routine servicing and care............................................................................17
9. D7 Meteo Multi FMD760...............................................................20
9.1. afety instructions.........................................................................................20
9.2. Intended use...................................................................................................20
9.3. Improper or unintended use...........................................................................20
9.4. Introduction...................................................................................................20
9.5. Overview of intelligent weather sensors.......................................................21
9.6. Putting into service........................................................................................22
9.7. Measuring quantities and ranges - factory default settings...........................22
9.8. Configuration via the sensor menu................................................................22
9.9. ensor functions............................................................................................24
9.10. Limitations when operating without an external supply...............................24
9.11. Operating modes of the device heating.........................................................24
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9.12. Operating modes of fan.................................................................................24
9.13. Energy saving mode 1...................................................................................25
9.14. Technical data................................................................................................25
10. D7 GPS positioning sensor FGD701..............................................27
10.1. Configuration via the sensor menu................................................................27
11. D7 thermocouple plug ZTD700 FS................................................29
11.1. Pin assignment..............................................................................................29
12. D7 Pt1000 plug ZPD710 FS...........................................................31
12.1. Pin assignment..............................................................................................31
13. Your contact partner......................................................................32
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ALMEMO® D7 digital sensors
The latest ALMEMO® D7 digital sensors have been designed to overcome all the limita-
tions experienced with earlier sensors regarding measurable variables, speed, range of
measured values, and number of channels per sensor. It is also possible to perform effi-
cient measuring operations simultaneously using high-speed and low-speed sensors with
any range of measured values. It is even possible, via a menu stored in such sensors, to
configure and use new measuring functions and quantities which ALMEMO® devices do
not themselves support. All this makes the new ALMEMO® D7 system flexible and su-
stainable beyond compare. Communication between sensors and the measuring instru-
ment is usually handled over a serial interface. D7 sensors can for this reason only be
used in conjunction with new ALMEMO® V7 devices. A sliding average can be confi-
gured internally for up to four primary channels.
1.Operation as sensor on ALMEMO® V7 measuring instruments
ALMEMO® D7 sensors supply their definitive digital measured values from up to 10
measuring channels virtually simultaneously over the serial interface to the ALMEMO®
V7 device where they are saved and / or output. Function channels can only be program-
med and used by the device itself. If the user prefers that a particular measuring channel
should not be displayed the measuring quantity and range can be switched off and deacti-
vated as usual via the ALMEMO® device; it can be reactivated in the same way. The
sensor is powered via the measuring instrument.
Extension
The operating radius of these sensors when connected to a measuring instrument can
be extended by means of extension cable ZAD700-VKxx; measured values and
connector programming can then be transmitted interference-free in serial form via an
R -422 driver. For electrical isolation adapter cable ZAD700-GT can be used.
1.1.Atmospheric pressure measurement and compensation
ome measurable variables (those in the measuring range list marked 'with PC') are af-
fected by atmospheric pressure and failure to take account of this may lead to substantial
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errors. To ensure the highest possible level of accuracy these D6 sensors are fitted as
standard with an atmospheric pressure sensor; this is always used automatically for atmo-
spheric pressure compensation (PC) - even if the particular channel is not activated. The
atmospheric pressure is programmed by default as a climate variable and can thus be
configured as reference function (s.6.3.6); the measured value can thus also be used to
compensate other sensors.
1.2.Correction of measured values
For the primary measuring channels adjustment values or multi-point adjustment can
be stored in the D7 sensor (either at our factory or via a V7 measuring instrument using
option KL). Correction values (zero-point, gain, base value, factor) are already proces-
sed in the sensor.
1.3.Sensor menu
To ensure the long-term future sustainability of the new ALMEMO® V7 measuring
system without having to change the measuring instrument each D7 sensor incorpora-
tes an individual sensor menu which can be downloaded over the serial interface. It is
possible in this way to configure measuring quantities and ranges, the averaging times
for measured value smoothing, or other specific sensor functions. As operating device
either a new ALMEMO® V7 measuring instrument or a PC can be used.
1.4.Configuration on PC via USB adapter cable
The ALMEMO® D7 sensor can be connected directly to a PC using U B link adapter ca-
ble ZA1919-AKUV at a baud rate of 115.2 kilobaud. A microcontroller incorporated in
the adapter cable automatically sets the power supply, baud rate, and device address that
the sensor requires.
To run the sensor menu via the PC the ALMEMO® Control software should be used
(from V. 5.14.0.330 up). The ' ensor menu' is located in the measuring points list under
'Edit'. Here it is possible to program up to 10 measuring points with specific D7 measu-
ring quantities and ranges for the D7 sensor and also other settings. The measuring quan-
tities and ranges are shown at the interface using new clear and informative abbreviati-
ons. Not only the quantity and range are programmed but also automatically the units
(up to six characters) and a comments text; and the channel is then locked at level 5.
Ranges can be deleted by selecting '- - - -' in the list.
Function channels * are determined in the measuring instrument - either as parameters
or the result of calculations. They can therefore only be programmed and used by the de-
vice itself. The following function channels are available :
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Batt, Mess, Alrm, Diff, Max, Min, M(t), n(t), M(n), Flow, Time
However, if connected directly to the PC, these are not available. The advisory note '!
unusable' will be displayed in the comments text.
Further parameters, depending on sensor type, can be set (e.g. setpoint adjustment, tem-
perature / atmospheric pressure compensation).
Atmospheric pressure compensation
If the sensor incorporates an atmospheric pressure sensor atmospheric pressure compensati-
on is set by default to ' ensor'; the current measured value is displayed under 'Value'. Ho-
wever, if a particular value needs to be used (e.g. altitude above sea level, weather forecast,
channel), this value can be programmed in menu item 'Value'. It is also possible, by simply
clicking on the 'Reference' option here, to use the measured value 'Atmospheric pressure' to
compensate other sensors connected to the same ALMEMO® device. This programs ab-
breviation '*P' in the comments text of measuring channel 'D AP', thus ensuring that this
measured value is always available in the ALMEMO® device for the purpose of atmosphe-
ric pressure compensation (s.Man. 6.3.6).
Averaging period (smoothing)
All measured values on the primary channels are internally scanned all the time at the indi-
vidual refresh rate. On most D7 sensors if measuring conditions make these values too uns-
table an averaging period can be entered in the menu for the primary channels; measured
values will then be smoothed by a sliding average.
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2.D7 UI connectors ED700-FS, ED701-FS, ED702-FS
D7 connectors are used, depending on connector type, to record voltages and currents in
three different variants and each of these at two rates; they do so by means of an integrated
24-bit delta-sigma A/D converter. At five measuring operations per second (mops)
200,000 digits can be acquired or at 500 mops, 20,000 digits. The necessary sensor supply
(U+) and (Gnd) can be set via the device itself at 6, 9, or 12 V. The 4-wire configuration
avoids measuring errors resulting from a voltage drop on Gnd.
Measuring quantities and ranges factory default settings
Designation M/s Quantity Measuring range Units Resolution
ZED700-FS
1. * U2.00000 5B-01 D U25 -2.2...+2.2 V 0.01 mV
2. U2.0000 5OO B-02 D U24 -2.2...+2.2 V 0.1 mV
3. U2.000 1000 B-03 D U23 -2.2...+2.2 V 1 mV
ZED700-FS2
1. * U250.000 5B-01 D U254 -250...+250 mV 1 uV
2. U64.000 5B-02 D U643 -64...+64 mV 1 uV
ZED70 -FS
1. * I20.0000 5B-01 D I2O4 -20.0...+20.0 mA 0.1 uA
2. I20.000 5OO B-02 D I2O3 -20.0...+20.0 mA 1 uA
3. I20.00 1000 B-03 D I202 -20.0...+20.0 mA 10 uA
ZED702-FS
1. * U20.0000 5B-01 D U2O4 -20.0...+20.0 V 0.1 mV
2. U20.000 5OO B-02 D U2O3 -20.0...+20.0 V 10 mV
3. U20.00 1000 B-03 D U2O2 -20.0...+20.0 V 10 mV
The preset measuring quantities and ranges are indicated by an asterisk (*).
2.1.Pin assignment
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Technical data
Input resistance 110 kΩ ( ED700/702)
100 + 30 Ω ( ED701)
Overload approx. 50%
A/D converter Delta-sigma
Accuracy (5mops) 0.02 % ±2 digits
Temperature drift maximum 30 ppm/K
Nominal temperature +22 °C ±2 K
Refresh rate 200 ms (5 mops), 2 ms (500 mops)
Power supply 6 / 9 /12 V from the ALMEMO® measuring instrument
Power consumption approx. 7.5 mA (5 mops), approx. 9.5 mA (500 mops)
Connector colors Housing ruby red, levers black
3.D7 Pt100 connector PD70x-FS
D7 Pt100 connector ZPD700-F is used to record the sensor's temperature at the highest
possible level of precision across the entire range from -200.00 up to +850.00 °C without li-
nearization errors; it does so by means of an integrated 24-bit A/D converter. ince the
sensor does not depend on an evaluating unit for its overall accuracy, it can undergo cali-
bration and even multi-point adjustment independently. For a 3-wire configuration connec-
tor ZPD703-F is available. The level of accuracy in this case depends on the difference in
the line resistances.
Measuring quantities and ranges factory default settings
Designation Quantity Measuring range Units Resolution
ZPD700-FS 4-wire
1. Pt100 10mops B-01 DPO4 -200.00...+850.00 °C 0.01 K
ZPD703-FS 3-wire
1. Pt100 10mops B-01 DPO3 -200.00...+850.00 °C 0.01 K
3.1.Pin assignment
4-wire connection
3-wire connection
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Technical data
Uses Temperature (depending on sensor type)
Temperature sensor PD700-FS Pt100, 4-wire
PD703-FS Pt100, 3-wire
Measuring quantities and ranges Temperature -200.00 to +850.00 °C
A/D converter Delta-sigma
System accuracy 0.07 K ±2 digits
Temperature drift maximum 30 ppm/K
Nominal temperature +22 °C ±2 K
Refresh rate 0.1 seconds
Self-calibration 12.8 seconds
Supply voltage 6 to 13 VDC
Current consumption approx. 8.5 mA
Connector colors Housing ruby red, levers black
4.D7-Potentiometer connector WD700-FS
D7 potentiometer connector ZWD700-F , operating at 100 measuring operations per se-
cond, is used to record the voltage drop at a potentiometer sensor fed with a 2V reference
voltage from its integrated 24-bit A/D converter.
Measuring quantities and ranges factory default settings
Designation Quantity Measuring range Units Resolution
1. Poti 100mops B-01 D U24 0.00...+100.00 % 0.01 %
4.1.Pin assignment
Technical data
Measuring range 00.00 to 100.00 %
A/D converter Delta-sigma
System accuracy 0.02% ±2 digits
Temperature drift maximum 30 ppm/K
Nominal temperature +22 °C ±2 K
Refresh rate 0.01 seconds
Supply voltage 6 to 13 VDC
Current consumption approx. 8.0 mA
Connector colors Housing ruby red, levers black
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5.D7 bridge connector KD700-FS
D7 bridge connector ZKD700-F is used to record the output voltage of a 4-wire full
bridge with a 5V supply (5V, Gnd); it does so by means of an integrated high-speed 24-
bit A/D converter. It is thus possible to record dynamic changes in force by means of
wire strain gauges at two different conversion rates, namely 10 or 1000 measuring opera-
tions per second. Connection is via four screw terminals.
Measuring quantities and ranges factory default settings
Designation Quantity Measuring range Final value Units Resolution
1. Kraft 1000mops B-02 DMS2 0..+50000. 50000 xx 1 xx
Adjustment is performed by means of internal high-precision resistors each time the de-
vice is switched on, a sensor is connected, or there is a change in the quantity being mea-
sured. Depending on the specifications of the wire strain gauges the measuring channel
must be programmed with the required units. caling is performed via the sensor menu
either on the V7 measuring instrument or on the PC.
5.1.Configuration via the sensor menu
The following two measuring ranges can be configured. (* factory default settings)
Designation Quantity Measuring range Final value Units Resolution
1. Kraft 10mops B-01 DMS1 0..+200000. 200000 xx 1 xx
2. * Kraft 1000mops B-02 DMS2 0..+50000. 50000 xx 1 xx
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5.2.Sensor adjustment and scaling
These two quantities offer two different conversion rates and thus also different measuring
ranges and resolutions. It is important to strictly adhere to each of the maximum final valu-
es including the decimal point.
For the purpose of zero adjustment the 'ZERO' key is provided.
For configuring the sensor's individual gain and scaling there are two possible procedures.
1. If the sensor was supplied with a specific 'characteristic value ' in mV / V, this can
easily be entered in the sensor menu; scaling will then be performed with the final
value and decimal point.
2. Or, alternatively, the indicator can be deleted and the sensor can be subjected to a
force equivalent to the final value. caling will then be performed, similarly,
using the final value and the decimal point. Pressing the 'ADJ' key will adjust the
gain accordingly.
For taring purposes the standard function for 'zero-setting' the measured value is available.
5.3.Pin assignment
Technical data
Power supply from 6 V up, from the ALMEMO® device itself
Bridge voltage 5 V stabilized (terminals 5V and Gnd)
A/D converter Delta-sigma, ratiometric (Bridge voltage = reference)
Common-mode range 0.25 to 4.75 V
Input range -29.300 to +29.300 mV (terminals In+ and In-)
Display range 0 to ±200,000 (range DMS1 at 10 mops)
0 to ±50,000 (range DMS2 at 1000 mops)
Accuracy (10mops) 0.02% ±2 digits
Temperature drift maximum 30 ppm/K
Nominal temperature +22 °C ±2 K
Self-calibration Each time the device is switched on or a sensor is connected
Refresh rate DMS1 100 ms, DMS2 1 ms
Current consumption approx. 15.5 mA
Connector colors Housing ruby red, levers black
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6.D7 tensile and compressive force sensors FK0xx
D7 tensile and compressive force sensors FK0xx incorporate wire strain gauges in the
form of a 4-wire full bridge; these are fed via the electronics in the plug on connecting
cable ZKD712F with a 5V bridge supply and are evaluated via a high-speed 24-bit A/D
converter. It is thus possible to record dynamic changes in force at two different conver-
sion rates, namely 10 or 1000 measuring operations per second. To adjust the final value
these sensors incorporate an internal adjustment resistor which can be activated as and
when required via the sensor menu.
Measuring quantities and ranges factory default settings
Designation Quantity Measuring range Units Resolution
1. Kraft 1000mops B-02 DMS2 + + +
+ Measuring range, units, and resolution depending on type (see data sheet)
6.1.Configuration via the sensor menu
The following two measuring ranges can be configured. (* factory default settings)
Designation Quantity Measuring range Units Resolution
1. Kraft 10 mops B-01 DMS1 + + +
2. * Kraft 1000 mops B-02 DMS2 + + +
+ Measuring range, units, and resolution depending on type (see data sheet)
6.2.Sensor functions
The user can set the sensor to zero at any time by pressing the 'ZERO' key. These two
quantities are scaled by means of the factor according to the sensor's measuring range
and at the conversion rate providing the highest resolution. Users wishing to scale the
sensor themselves (e.g. to other units) can enter the required final value and the decimal
points and then for the purposes of adjusting the gain activate the internal 'calibration re-
sistor' corresponding to the final value and press the 'ADJ' key.
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6.3.Technical data ZKD712 FS
s. page 11
7.D7 pressure sensors FD0602Lxx
Pressure sensors FD0602Lxx are used to record output voltage (0.2 to 2.2 V) in two possi-
ble resolutions and conversion rates; they do so by means of an integrated 24-bit delta-sig-
ma A/D converter incorporated in the connector of adapter cable ZDD702AKLxx. At five
measuring operations per second (mops) 200,000 digits can be acquired or at 500 mops
(factory default setting), 50,000 digits. Exact details regarding the sensor's measuring
quantities and ranges, units, conversion rate, and resolution are provided, depending on
type, in the respective data sheets.
In case the measuring range respectively the measuring rate is reprogrammed,
the scaling values will be deleted. The scaling must then be reprogrammed (e.g.
by using the ALMEMO® Control software).
7.1.Technical data ZDD702AKLxx
Input 0.2 to 2.2 V 4-wire configuration
Output 0 to 200,000 (range DMS1 at 5 mops)
0 to 50,000 (range DMS2 at 500 mops)
A/D converter Delta-sigma
Accuracy (5mops) 0.02% ±2 digits
Temperature drift maximum 30 ppm/K
Nominal temperature +22 °C ±2 K
Refresh rate 200 ms (5 mops), 2 ms (500 mops)
Power supply 9 V from the ALMEMO® measuring instrument
Power consumption approx. 11 mA, DMS1 including sensor
approx. 13 mA, DMS2 including sensor
Connector colors Housing ruby red, levers black
7.2.D7 pressure sensors FD8214xx
Pressure sensors FD8214xx are used to record output voltage (0 to 2.0 V) in two possible
resolutions and conversion rates; they do so by means of an integrated 24-bit delta-sigma
A/D converter incorporated in the connector of adapter cable ZDD714AKxx. At five mea-
suring operations per second (mops) 200,000 digits can be acquired or at 500 mops, 50,000
digits. Exact details regarding the sensor's measuring quantities and ranges, units, conversi-
on rate, and resolution are provided, depending on type, in the respective data sheets.
7.3.Technical data ZDD714AKxx
Input 0.0 to 2.0 V 4-wire configuration
Other useful data see Chapter 7.1
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

8.D7 conductivity probe FYD741LF
8.1.Basic principles
The conductivity (unit /m = iemens/meter)
is a measure for the ion concentration in a
measuring solution. Conductivity is proportio-
nal to the amount of salt, acid, or base alkaline
content measured in the solution, High-purity
water has a conductivity of approx. 0.05 µ /
cm (at +25 °C), natural water approx. 100 to
1000 µ /cm, and some alkaline solutions (e.g.
potassium hydroxide solution) slightly more
than 1200 m /cm. The diagram on the left
shows further relevant examples of aqueous
solutions.
Standardization
The method for determining the electrical con-
ductivity of water is defined in DIN EN 27
888.
Temperature compensation
Conductivity is a temperature-dependent variable. For most diluted, aqueous salt solu-
tions within a certain temperature range conductivity is an approximately linear functi-
on of temperature T.
κT = κ25 (1+α(T-25°C)/100)
Conductivity, at reference temperature 25°C
κ25, is calculated as follows :
κ25 = κT / (1+α(T-25°C)/100)
The temperature coefficient α describes the
relative change in conductivity in % as the
temperature changes with respect to refe-
rence temperature 25 °C.
α = (κT - κ25) * 100% / κ25 (T-25)
Temperature coefficient α depends on:
● the chemical composition of the soluti-
on
● the concentration of the electrolyte
● the temperature, especially at low con-
ductivity levels of <1 µ and at very high
conductivity levels
- 14 -

8.2.Measuring principle
The conductivity in electrolytes is obtained via an electro-chemical resistance measure-
ment using a 4-electrode measuring cell. An AC voltage with a frequency of approx. 1
kHz is applied to the electrodes. The current flowing through the test object is conver-
ted into a voltage. This voltage is rectified via a true RM (TRM ) converter, smoo-
thed, and then fed to an 18-bit A/D converter. The temperature is measured by means
of an NTC sensor.
Measuring quantities and ranges
Two measuring channels (depending on type) are available (factory default settings).
Designation Quantity Measuring range Units Resolution
. Temperature D t See technical data for probe °C 0.01 K
2. Conductivity 50 mS DLF2 See technical data for probe mS 0.001 mS
The sensor is already adjusted on delivery and ready for use. Temperature compensati-
on is preset to a linear characteristic with a temperature coefficient of 1.90 %/K. In
the measuring operation the sensor must be lowered at least 30 mm into the liquid so
that the electrodes are completely immersed.
8.3.Configuration via the sensor menu
The sensor parameters (measuring quantity and range, temperature compensation, probe
adjustment) can be configured in the sensor menu either on a V7 measuring instrument
or on the PC using the ALMEMO® Control software (V. 5.14.0.330 and above).
Note: The ´ZERO´ and ´ADJ´ keys are only enabled if the
locking of the sensor (locking level 0) has been disabled.
8.3.1.Configurable measuring quantities and ranges
In the D7 sensor it is possible to configure not only the temperature range on the first
measuring channel but also any one of three conductivity ranges from the following list
on the second measuring channel. (* factory default settings)
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Designation Quantity Measuring range Units Resolution
1. Conductivity LF1 500 uS B-01 DLF1 0...500.00 uS 0.01 uS
2. * Conductivity LF2 50 mS B-02 DLF2 0...50.000 mS 0.001 mS
3. Conductivity LF3 500 mS B-03 DLF3 0...500.00 mS 0.01 mS
Ranges can be deactivated by selecting stops '- - - - -' in the list.
Note: The measurable quantity can only be changed while sensor locking is disabled
(locking level 0).
8.3.2.Cell constant
The cell constant is the indicator used for conductivity measuring cells as determined by the
size and geometric arrangement of the measuring electrodes. It remains virtually unchan-
ged. o long as the electrode surfaces are clean and free of any insulating deposits calibra-
tion is generally not necessary. However, after cleaning, repair, or probe replacement it
may be necessary to correct the cell constant. It can then be reset as part of a calibration
process using reference solutions. The cell constant is preconfigured to the following valu-
es. FYD741LFP: 0,500 FYD741LFE01: 0,550
Note: The cell constant can only be entered while sensor locking is disabled (locking level 0).
8.3.3.Setpoint
The probe adjustment method in which the cell constant is entered is generally less satisfac-
tory than the method of adjusting the measuring ranges on the basis of a reference solution.
In this method the conductivity of the reference solution is entered as setpoint and the probe
is then adjusted by pressing the 'ADJ' key. In so doing the cell constant is reset based on
the quality of the reference solution.
Note: The probe can only be adjusted while sensor locking is disabled (locking level 0).
8.3.4.Temperature compensation
For this probe, under menu item 'Temp.Comp.', three different settings are available.
Temp. Comp.:
Off No temperature compensation at low or very high conductivity values
Natural water Temperature compensation with non-linear characteristic for natural water and
high-purity water
Linear
characteristic
Temperature compensation with linear characteristic and settable temperature
coefficient
The linear temperature coefficient is entered in the next line
Temperature coefficient 1.90 %/K
If the temperature coefficient of a sample is not known, α can be defined experimentally.
We measure electrical conductivity values κ25 at (25 ± 0,1) °C and κT at a known tempera-
ture (T2 ± 0,1) °C; these values are then entered in the following equation α = (κT - κ25) *
100% / κ25 (T2-25) eingesetzt.
If measuring is performed without temperature compensation, the conductivity measured at
a known temperature can be converted to 25 °C using a correction factor.
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8.4.Routine servicing and care
Minor dust and dirt can be removed using a soft brush. Cleaning on a more intensive
scale, as required if the electrodes are very dirty, may result in the distances between
electrodes being slightly altered; this may have an adverse effect on results.
Checking
In the following circumstances it makes good sense to check the probe :
● in the event of the geometry changing (e.g. electrode spacing)
● after use in extreme conditions (e.g. high temperatures)
● if the probe produces measured results that are not plausible
Adjusting the D7 conductivity probe
A conductivity probe of this type is adjusted at two measuring points :
1. in a dry condition at 0 m /cm
sensor adjustment by pressing key 'ZERO'
2. in reference solutions as per measuring range
e.g. 147 μ /cm - 0.001 mol KCl reference solution at (25 ±0,1) °C
in measuring range 500 μ or
12.88 m /cm - 0.1 mol KCl reference solution at (25 ±0,1) °C
in measuring range 50 m
Enter setpoint (reference value) in function ' etpoint'
Sensor adjustment by pressing key 'ADJ'.
Throughout the adjustment procedure the solution must be kept at a constant
temperature (25 ±0.1)°C
The probe can also be adjusted outside of standard conditions (25 ±0.1) °C.
Zero-point adjustment is performed as described above. For the purposes of gain ad-
justment the value of the reference solution at a known temperature (see Table 1) is
compared with the deviating value determined on site; this ratio is manually entered as
correction value in the ALMEMO® plug under 'Gain correction' (GC).
Example
Adjustment of probe using 1 mol KCl reference solution at measured solution tempera-
ture 20.0 °C.
Value for reference solution at solution temperature 20.0 °C 102.09 mS cm (Table 1)
Measured value at solution temperature 20.0°C : 98.72 mS cm
Table 1:
Electrical conductivity κ in mS cm of KCL standard solutions
as a function of temperature t and concentration:
- 17 -

GC =Value for reference solution at solution temperature 20°C
Measured value at solution temperature 20°C
=102 09
98 72 =1 034

t [°C]
κ [mS/cm]
0,00 mol/l
κ [mS/cm]
0,0 mol/l
κ [mS/cm]
0,02 mol/l
κ [mS/cm]
,00 mol/l
0 0,776 1,521 65,41
1 0,800 1,566 67,13
5 0,896 1,752 74,14
10 1,020 1,994 83,19
15 1,147 2,243 92,52
16 1,173 2,294 94,41
17 1,199 2,345 96,31
18 0,127 1,225 2,397 98,24
19 0,130 1,251 2,449 100,16
20 0,133 1,278 2,501 102,09
21 0,136 1,305 2,553 104,02
22 0,138 1,332 2,606 105,54
23 0,141 1,358 2,659 107,89
24 0,144 1,386 2,712 109,84
25 0,147 1,413 2,765 111,8
Reference solutions are available as accessories specific to each conductivity range.
( ee our main product catalog, pages 16.06 and 16.07
olutions for calibrating conductivity probes are non-buffered systems. Their conduc-
tivity values are not stable; they are affected even by small amounts of contamination
or dilution (e.g. water droplets on the probe). This applies in particular at low conduc-
tivity levels.
Clean measuring cells
Before starting calibration it is important to ensure that the probe is clean. Any conta -
minant residues should be rinsed off using distilled water. The probe should be dried
and then rinsed with the recommended calibration solution.
Examples of typical conductivities
Distilled water < 5 μS/cm
Rain water 50-100 μS/cm
Drinking water 500 μS/cm
Mineral water > 1000 μS/cm
Industrial effluent 5 mS/cm
Sea water 50 mS/cm
1 mol/L NaCl 85 mS/cm
1 mol/L HCl 332 mS/cm
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Technical data
Probe FYD74 LFE0 FYD74 LFP
4-contact conductivity probe Laboratory electrode Process electrode
Measuring range
Conductivity
10 μS to 500 mS 10 μS to 200 mS
Accuracy
under nominal conditions
±2% of measured value
±0.2% of final value
±3% of measured value
±0.2% of final value
Temperature sensor NTC sensor 30 kΩ NTC sensor 10 kΩ
Temperature 0 to +80 °C 0 to +70 °C
Accuracy 0.2 °C 0.2 °C
Temperature compensation automatic / not compensated
Temperature coefficient Natural water / linear (α = 0.00 to 9.99)
Cell constant approx. 0.5 cm-1 approx. 0.5 cm-1
Electrode material Special carbon Special carbon
Nominal temperature 25 ±2 °C 25 ±2 °C
Operating temperature 0 to +80 °C 0 to +70 °C
Minimum immersion depth 30 mm 30 mm
Shaft material PC (+ABS) PVC - C
Shaft length / shaft diameter 120 mm / 12 mm 130 mm / 20 mm
Fitted length / thread - - - 145 mm / G ¾-inch
Maximum pressure unpressurized 16 bar at +25 °C
Connector ALMEMO® D7
Cable length 1.0 m 1.5 m
Supply voltage 6 to 13 VDC
Current consumption approx. 10 mA
Connector colors Housing ruby red, levers black
Refresh rate 2.5 seconds
A/D converter Delta-sigma, 18-bit resolution
Sleep mode on the device possible with sleep delay 5 seconds
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9.D7 Meteo-Multi FMD760
9.1.Safety instructions
•Assembly, installation, and putting into service should be performed
exclusively by appropriately trained and qualified specialist person-
nel.
•Measuring operations should never be performed on live com-
ponents; live components should never be touched.
•It is important to strictly adhere to the technical data, storage conditi-
ons, and operating conditions.
9.2.Intended use
•The device must only be operated according to the specified technical
data.
•The device must only be used under the conditions and for the purpo-
ses for which it has been designed.
•If the device is in any way modified or converted its working safety
and proper functioning can no longer be guaranteed.
9.3.Improper or unintended use
•If the device is not properly installed
•the device may not function properly or may not function at all
•the device may be permanently damaged
•the device may fall - with risk of injury to users
•If the device is not properly connected
•the device may not function
•the device may be permanently damaged
•there may be a risk of electric shock
9.4.Introduction
The Meteo Multi FMD760 is a compact, light-weight multi-sensor system for measuring all
important meteorological variables. From 17 possible measuring quantities and ranges -
temperature, relative humidity, atmospheric pressure, wind velocity, wind direction, rain,
snow, and hail - 10 variable combinations can be configured in the configuration menu and
recorded simultaneously.
With the connector adapter it is possible to warm the sensor, activate the fan, or just to save
the ALMEMO® device battery by using mains unit ZB1024NA2. (see Figure).
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