Kobold NMC User manual

Operating instructions
for
Capacitive level transmitter
Model NMC
2 Wire (4 to 20mA)

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1. Content
1. Content ....................................................................................................................... 2
2. Note ............................................................................................................................ 3
3. Instrument inspection .................................................................................................. 3
4. Description .................................................................................................................. 3
5. Application .................................................................................................................. 4
6. Current simulation ....................................................................................................... 4
7. Installation .................................................................................................................. 5
8. Electrical connection ................................................................................................... 6
9. Programming .............................................................................................................. 7
9.1 Calibrating probe .................................................................................................. 7
9.2 Output Adjustment ................................................................................................ 8
9.3 Output simulate .................................................................................................... 9
9.4 Language ........................................................................................................... 10
10. Technical Data ....................................................................................................... 11
10.1 Process temperature range ............................................................................ 12
10.2 Process pressure range .................................................................................. 12
11. Safety Instructions (ATEX) .................................................................................... 13
11.1 Validity ................................................................................................................ 13
11.2 General considerations ...................................................................................... 13
11.3 Protection against ESD (electrostatic discharges) ............................................. 13
11.4 Chemical resistance ........................................................................................... 13
12. Installation in classified zone (ATEX) ..................................................................... 14
13. Label Description (ATEX) ...................................................................................... 14
14. Declaration of conformity ATEX ............................................................................. 15
15. UE Declaration of Conformity ................................................................................ 16
16. UK Declaration of Conformity ................................................................................ 17
17. ATEX Certified ....................................................................................................... 18
18. Models ................................................................................................................... 23
19. Order details. ......................................................................................................... 24
Manufactured by:
Kobold Mesura S.L.U
Avda Conflent Nº68 Nave 15
08915 Badalona
Tel.: [phone]
Fax: [phone]
E-Mail: [email protected]
Internet: www.kobold.com
Edition: May 2022

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2. Note
Please read these operating instructions before unpacking and putting the unit in
operation. Follow the instructions precisely as described herein.
The instruction manuals on our website www.kobold.com are always for currently
manufactured version of our products. Due to technical changes, the instruction
manuals available online may not always correspond to the product version you have
purchased. If you need an instruction manual that correspond to the purchased
product version, you can request it from us free of charge by email
([email protected]) in PDF format, specifying the relevant invoice number and
serial number. If you wish, the operating instructions can also be sent to you by post
in paper form against an applicable postage fee.
The devices are only to be used, maintained and serviced by persons familiar with
these operating instructions and in accordance with local regulations applying to
Health & Safety and prevention of accidents.
When used in machines, the measuring unit should be used only when the machines
fulfil the EC-machine guidelines.
Please read these operating instructions before unpacking and putting the unit into
operation. Follow the instructions precisely as described herein.
The devices are only to be used, maintained, and serviced by persons familiar with
these operating instructions and in accordance with local regulations applying to
health & safety and prevention of accidents.
3. Instrument inspection
Instruments are inspected before shipping and sent out in perfect condition.
Scope of delivery
The standard delivery includes:
 Capacitive Level Transmitter NMC
 Cable gland M20
 Operating Instructions
4. Description
The NMC transmitter is a two-wire capacitance level transmitter for measuring
continuous level in tanks containing liquids.

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5. Application
The probe of the NMC and the wall of the tank, forms an electric capacitor. The
dielectric of this capacitor when the tanks is empty, is the air.
When the liquid reaches the probe, the dielectric constant formed by the unit and
tank, changes.
An electronic circuit sited in the connecting module of NMC, converts this capacity
change in a variable current and proportional to the height of the liquid.
Due to each application is different, given that the kind and the measures of the tank
and the products that it contains change, every unit must to be adjusted to be adapted
to each tank and product.
Using the menus of the NMC, this operation is very easy.
The circuit, controlled by microprocessor, stores all data and does the calculation. A
display LCD guides us in the calibration process.
The output current signal is 4 to 20 mA. These values can be sited where we want in
the probe.
6. Current simulation
Using this option, the NMC generates in the supply loop, a 4 to 20 mA current, in
steps of 1 mA. This function is very useful to make tests with independence of the
level of the tank.

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7. Installation
The NMC is installed using a G1” (G2” in DS version).
The probe must be installed avoiding a good contact between the probe and the
tank’s wall.
Electronic of the NMC unit should be protected with shelter against development of
too high temperature by direct sunshine.
Be ensured that the connection to the tank has been done properly. The NMC ’s
thread should not be forced.
The electrical connection between the thread and the tank must to be good.

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8. Electrical connection
The maximum resistance of the line in serial, depends on the power supply. These
values have to be bear in mind for the good run of the NMC.

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9. Programming
9.1 Calibrating probe
Pressing any key, you enter in the main menu.
Press (OK) to enter in calibration probe.
To avoid mistakes, asks again if you are sure that,
you want to calibrate the unit. Press (OK) another
time to enter.
If the level in the tank is low, we will choose the (OK)
option to adjust the unit with the lowest level.
If, for example, when you adjust the low level, the level
of the tank is the 0 % of the capacitance, we will
indicate it in the display using the (+) and (-) keys.
Confirm with (OK).
In this moment the microprocessor makes the
operations to choose the best measurement range.
This operations takes some seconds.
When this operation is finished, the display shows the
message “PROBE CALIBRATED”.
Automatically the display show the main menu.
Now need calibrate the High Level, then pressing (OK)
another time to enter in the calibration probe menu.

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To avoid mistakes, asks again if you are sure that you
want to calibrate the unit. Press (OK) another time to
enter.
Pressing (+) we enter in High level calibration.
If when you adjust the high level, the liquid in the tank is
100 % of the capacitance, we will indicate it in the
display using the (+) and (-) keys. Confirm with (OK).
The microprocessor makes the operations to calibrate
the maximum level of the unit. This operation takes
some seconds.
The display shows this message to indicate NMC has
finished the calibration internal process.
When the liquid level will be in the minimum point, it will
indicate 000.0 % and when the liquid level will be in the
maximum, 100.0 %.
Automatically, the display shows the main menu.
Pressing ESC the unit return to read state.
Pressing (+) we can enter in output adjustment.
menu and simulation mode.
9.2 Output Adjustment
Pressing any key, you enter in the main menu.
Press (+) to enter in Output.

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Pressing (+), we enter in Output adjustment menu.
This asks, where do you want the NMC gives us mA. If
you want it in 0 % of the probe. Using (+) and (-) we
indicate this value in the display. Confirm with (OK)
We do the same for the 20 mA. In this case, if we want
this current in the 100 % of the probe, we will indicate
this value using (+) and (-). Confirm with (OK)
Finished the adjustment, we can incorporate a filter to
avoid oscillations caused by quick movements of the
liquid’s surface. This value between 0 and 5 (maximum
filter). Confirm with (OK)
Automatically return to output menu.
Pressing ESC return to measuring mode.
In this point, the NMC is adjusted. The number in %
indicates the height that reaches the level in the probe
(0 to 100). The value of the current will depend of the
adjustment of the points 3 and 4 of this section, and it
can be in any point of the probe. It can be in maximum
point and in the 20 mA at the minimum.
9.3 Output simulate
Pressing any key, you enter in the main menu.
Press (+) to enter in Output.

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Pressing (-), we enter in simulate output menu.
In this screen, using the (+) and (-) keys, the loop
current (2 wire) will change in steps of 1mA. With this
option, you can do current testes without generator.
Pressing (OK) return to menu show in point 2.
Pressing (ESC) return to read mode.
9.4 Language
Pressing any key, you enter in the main menu.
Press (+) to enter in Output.
Pressing (+) or (-) we can choose the language for the
display.
Language available: Spanish, English, German, Italian,
French, Portuguese, Catalan.
Pressing (OK) return to main menu in language
selected.