METROTEC GSM-V6 User manual

Oxygen measurement and control unit
Typ GSM
*** Version 2.1 ***
METROTEC
S yst ems fo r o xyg en mea s u re men t
GSM
-
V6

METROTEC
Declaration of Conformity
for
Oxygen measurement and control unit
GSM-V6
This device has been designed for industrial purposes in accordance with:
EN 61000-6-4
EN 61000-6-2
It is compliant with the directives:
EMC Directive: 2014/30/EU
Low Voltage Directive: 2014/35/EU
RoHs: 2011/65/EU
This device complies with following standards:
EN 61010-1
EN 61000-6-4
EN 61000-6-2
EN 63000
Description of measures taken to assure compliance:
Quality management system DIN EN ISO 9001:2015, No. 12 100 27736 TMS
This declaration becomes invalid if changes are made without
our consent.
Kirchheim/Teck, 07.10.2019
Place, Date Signature
© 2019 METROTEC GmbH
Heinkelstraße 12 • D-73230 Kirchheim
Telefon [phone] • Fax [phone]
www.metrotec.eu • [email protected]

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Contents
1 SAFETY INSTRUCTIONS........... 4
2 PREFACE ...................................... 5
3 INTRODUCTION ......................... 6
3.1 Measurement principle ............. 6
3.2 Measurement electronics .......... 7
3.3 Sensor ...................................... 7
4 GENERAL ARRANGEMENT ..... 7
4.1 Description of the measurement
electronics ........................................... 8
4.2 Description of the sensor.......... 8
4.3 Sketch of the ducting system .. 10
5 PUTTING THE UNIT INTO
OPERATION....................................... 11
5.1 Switching the unit on ............. 11
5.2 Measurement.......................... 11
5.3 Bottled gases.......................... 11
5.4 Process gases ......................... 11
5.4.1 General .......................... 11
5.4.2 Hot process gases........... 11
5.4.3 Special process gases ..... 11
5.4.4 Location of condensate
collectors12
5.4.5 Filter system arrangement:
12
5.5 Switching off the measurement
unit 12
6 OPERATION............................... 13
7 CONFIGURATION..................... 17
7.1 Enablement of Configuration ..17
7.2 Displayed values.....................18
7.3 Process parameters .................19
7.4 mA outputs .............................19
7.5 Alarm output ..........................21
7.6 Control output.........................21
7.7 Scaling of the trend graphs......22
8 OPTIONS .....................................22
8.1 Dew point ...............................22
8.2 Lambda ..................................23
8.3 CO..........................................23
8.4 Calculated oxygen value .........23
9 INTERFACES ..............................24
9.1 Analog interfaces....................24
9.2 Digital interfaces ....................24
9.2.1 Standard interfaces .........24
9.2.2 Optional interface: RS 485
25
9.2.3 Optionale interface:
Ethernet 28
10 SPECIAL FEATURES.................29
10.1 Correction factors ...................29
10.2 Filter factor.............................30
10.3 Oxygen controller ...................30
10.4 Coding....................................31
10.5 Function of the clock ..............31
11 TECHNICAL DATA....................32
12 CONNECTION PLAN.................33

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1 Safety instructions
&Please read through this operating manual very carefully before in-
stalling and commissioning the unit.
Incorrect utilisation will invalidate the guarantee!
Correct functioning and the operating safety of the unit can only be
guaranteed if the ambient conditions specified in the Specifications
chapter are maintained.
Only qualified specialists are permitted to commission and operate
the unit. The owner of the unit must ensure that the installation com-
plies with the relevant laws and directives. These include, for exam-
ple, the EU Directives covering safety in the workplace, national
safety in the workplace regulations and the prevention of accidents
regulations, etc.
You must ensure that the power supplies concur with the details
listed on the nameplate. All of the covers needed to ensure that the
unit cannot be touched when operating must always be fitted. You
must consider the effects of the overall operation and take the neces-
sary precautions if the unit will be linked up with other equipment
and/or devices before you switch on.
Parts and surfaces will occasionally become and remain hot during
the installation or de-installation. Suitable precautions must be taken
in order to prevent injuries or damage to the unit from occurring.
If the unit shows signs of having been damaged and you are of the
opinion that that safe operation is no longer possible then you must
not run the unit. We recommend that periodical inspections are car-
ried out at our factory or by our customer service department at least
once a year.
Future disposal must always comply with the legal regulations.

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2 Preface
With the aid of an oxygen sensor , the measurement unit serves to measure the oxygen partial
pressure in gaseous atmospheres. Such sensors work at high temperatures and so it is neces-
sary for measures to be taken to ensure that no flammable gas mixtures contact the sensor or
the unit. In the event of the sensor ceramic suffering breakage the measurement gas could es-
cape or air could enter the measurement gas side of the unit and so suitable measures have to
be taken to avoid such an event leading to environmental pollution or damage being done to
equipment.
In the event of incorrect parameters being set or the occurance of leakage, corrosion,
condensation, etc., damage could be done to the equipment and incorrect measurement
results be indicated and so it is essential that all parts of equipment be regularly
serviced.
The oxygen sensor and its accessories are subjected to
thorough quality control in accordance with DIN ISO
9001 in the course of their manufacture and testing.
They must only be installated and used in compliance
with all applicable local and special regulations, partic-
ularly the VDE and DVGW standards that apply in Ger-
many.
The measurement accuracy and effective function of the
measurement device will need to be checked at intervals
whose frequency will depend on the applicaton con-
cerned. Such a check must be effected in the course of a
calibration and examination check on the equipment be-
ing first put into operation.

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3 Introduction
3.1 Measurement principle
Oxygen measurement units are designed to process signals transmitted from an ox-
ygen sensor constructed of stabilized zirconium oxide. Zirconium oxide, a ceramic
material that is also spoken of as a solid-state electrolyte, acts as an excellent oxy-
gen-ion conductor when at a high temperature.
Within certain temperature limits, that depend on the doping of the material con-
cerned, such ion conductors are able to fill empty spaces in their crystal lattice with
oxygen ions. The oxygen ions occur against an electrically conductive surface that is
generally of platinum.
The concentration of oxygen in a measurement gas is thus decisive for the extent of
oxygen activity, and thus for the number of oxygen ions.
An oxygen sensor consists essentially of a solid-state electrolyte with a contact sur-
face on both sides.
One side of the electrolyte is in contact with a reference gas such as air, and the oth-
er with the gas whose oxygen content is to be measured. The mechanical construc-
tion of the sensor prevents contact between the two gases so that there is no risk of
their being intermixed.
Depending on the application concerned, heated or unheated sensors are used. Un-
heated sensors are generally used in furnaces while heated sensors are used for ap-
plications where the gas to be measured is at a temperature of less than around 600
degrees Celsius (the measurement principle necessitates the sensor being main-
tained at a temperature of not less than 500 - 650 degrees Celsius).
Heated sensors are maintained at a set temperature by an electronic temperature
regulator that forms part of the electronic control unit. The temperature of both heat-
ed and unheated sensors as measured by the electronic control is an important pa-
rameter for inclusion in the calculation of the oxygen content (oxygen partial pres-
sure) in accordance with the following equation:
EMF R T
F
P
P
=
×
××
4
1
2
ln( )
whereby:
R = 8.31J/mol K
T = Temperature in Kelvin
F = 96493 As/mol
P
1= Oxygen partial pressure on the reference side with 0.20946
bar
P
2= Oxygen partial pressure on the measurement gas side
EMF = Electromotive forcein Volts

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3.2 Measurement electronics
The electronic circuit of the measurement unit Type GSM provides the following functions:
Measurement of the oxygen partial pressure
Maintaining the oxygen content at a preset level
Generating alarm signals
Option: Calculation of the dew point
Option: Calculation of the air factor lambda point
The device is operated with the aid of a keypad.
Menus assist the operator in the selection of inputs and outputs
and in the setting of parameters.
3.3 Sensor
The sensor of Type A04 is built into the front panel. It includes the actual measurement ele-
ment of platinum-plated zinc oxide, the heating element needed to heat-up the measurement
element to the minimum temperature of 700 degrees Celsius and the thermocouple needed to
detect the exact temperature at all times.
The front panel also carries a bypass valve, an illuminated flow meter, gas inlet and outlet
connections and also a potentiometer for adjusting the delivery of the gas pump if one is fitted
to ensure a flow of the gas who's properties are to be measured.
4 General arrangement

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3
4
2
1
5
4.1 Description of the measurement electronics
The elements at the front of the unit are in three groups
Keypad:
The keypad has four keys by means of which all the necessary functions can be effected.
Display:
The graphic display provides for the display of measured values, data, time graphs and mes-
sages.
4.2 Description of the sensor
1 Gas outlet
2 Flow meter
3 Bypass valve
4 Pump power
5 Gas inlet
When the power supply to the measurement unit is switched on the sensor is heated for a pe-
riod of 10 - 25 minutes to bring it up to the required minimum temperature.
NOTE: During the heating-up period the unit does not indicate any useable values.

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When the gas inlet is opened and the gas pump is switched on, the unit should indicate
20.9 % O2. If necessary, a correction can be made as detailed under "Correction" in the oper-
ating instructions.
The gas who's properties are to be measured is then fed to the sensor. The rate of flow should
be within the green, background illuminated region of the flow meter and should never be al-
lowed to exceed the range of the flow meter (this is a point of particular importance when the
gas comes from a gas cylinder).
An excessive rate of flow could result in the destruction of the sensor
The rate of flow can be set with the aid of the bypass valve and of the potentiometer that ad-
justs the delivery of the gas pump.
When the bypass valve is fully open the full flow of gas enters the measurement unit while a
rate of flow some five times greater than occurs when the bypass valve is closed is constantly
indicated.

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4.3 Sketch of the ducting system

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5 Putting the unit into operation
5.1 Switching the unit on
Once all electrical connections have been made and checked, the power plug is plugged in.
After waiting for about 15 minutes for the sensor to be heated up, the unit indicates the oxy-
gen content of the gas concerned. but stable values are only indicated about fifteen minutes
after the heating-up period has expired.
5.2 Measurement
Once the switching-on operation is completed, the unit is ready for operation and the oxygen
content of gases can be measured. As explained above, it is important to prevent the flow of
gas exceeding the range covered by the flow meter.
5.3 Bottled gases
No special gas-treatment measures are called for when measuring the properties of such syn-
thetic gases as nitrogen, argon, helium, etc. It is only necessary to provide for pressure reduc-
tion and precision dosing.
5.4 Process gases
5.4.1 General
It is not possible to give exact details of the measures needed for the avoidance of damage be-
ing done to the sensor and for correct pretreatment of all the many technical gases that may
call for measurement but it is generally necessary for the gas to be free of dust and condensate
and of any component that could suffer condensation. Such components could block the gas
passasges in the sensor result in it being damaged.
5.4.2 Hot process gases
If it is required to measure the properties of hot gases, the gas is withdrawn from the process
and subjected to suitable treatment before being fed to the sensor. The withdrawal duct may
be of metal or of ceramic material, depending on the temperature concerned. In most cases no
special means of cooling is needed for the small amount of gas needed for measurement as it
cools down on its own to around room temperature on its way to the measurement unit. It is
important to avoid there being any leakage in the piping.
5.4.3 Special process gases
There are a great many processes in which the process gas contains components that generate
liquid or solid condensate when beneath a certain temperature. Such condensates could be de-
posited in the gas passages in the sensor and affect the measurement results or cause the sen-
sor to be damaged. Before starting to make measurements, it is recommended that the pres-
ence of such components be investigated and that steps be taken to filter out any that are
found.

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5.4.4 Location of condensate collectors
When fitting a condensate collection vessel, especially one for water, it should be ensured that
it is located at the lowest point in the entire piping system..
It should be borne in mind that the filling of empty space in condensate collectors and filters
will result in some delay in effecting measurements
5.4.5 Filter system arrangement:
The provisions made for the pretreatment of gases to be measured need to be adapted to the
task concerned.
A standard system generally includes:
1. An initial water separator which may be equipped to empty itself of any condensate it
2. may collect.
3. A coarse filter for the filtration of particles with a grain size exceeding 50 m.
4. (Only necessary where a great deal of dust is involved)
5. A fine filter for the filtration of particles with a grain size exceeding 25 m.
6. It is advantageous for this filter to be equipped to close off the gas flow immediately
in the event of any liquid being applied to it's filter element.
5.5 Switching off the measurement unit
It is preferable for the unit to be kept in continuous operation. As the sensor then remains
heated there is less risk of it suffering the presence of condensation. that could lead to corro-
sion but if it is required to put the unit out of operation, the power plug should be withdrawn
and attention be paid to the following points:
Heated sensors:
Inline sensors:
Remove carefully while still hot and allow to cool, taking care to avoid mechanical or thermal
stress!
Compact sensors:
Flush with air before switching off
Unheated sensors:
These are generally left in place
Putting the measurement unit briefly out of operation:
When the unit is switched on again after being switched off for a short time, the instructions
given above under "Switching the unit on" should be followed.

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6 Operation
A few seconds after switching on, the first page is displayed as follows:
Each page has a headline that is separated by a line from the rest of the display. This headline
indicates the page number and the title or an outstanding fault message. Beneath the line there
is either a graph or a 6-line text.
The keypad has five components.
ÞOn the extreme left there is a rubber cap that is only removed to allow access to the socket
beneath to which the communication cable is connected when it is required to install a new
program.
ÞThe adjacent key provides for switching between manual and automatic operation.

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ÞThe two arrow keys provide for moving the cursor line upwards or downwards or for in-
creasing or decreasing values when alterations to entry fields are enabled.
ÞThe key on the right provides for
a) Opening a display page
b) Opening an entry field to enable an entry to be made
c) Closing an entry field and storing an entry.
ÞThe “Esc” key is for closing the display page or return to overview
Pressing the right-hand key causes the display to jump to the page selection list and then the
cursor bar can be moved to the line bearing the required page title. When this no longer illu-
minated page title is confirmed by pressing the right-hand key, the page concerned is dis-
played.
An opened page can be closed again by pressing the right-hand key.
A window opens for any inputs. Like below example values can stored by pressing the but-
tons. „Min“ and „max“ shows the limit values. „Cu“ shows the current value. Store by press-
ing „OK“.
The various pages that can be selected in normal operation are detailed below.

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7 Configuration
7.1 Enablement of Configuration
Before parameters can be altered it is first necessary to overcome the disablement code. Only
then is access to additional pages possible. Enablement is effected as follows:
1. Select the page entitled CODE in the page selection table.
2. Press the key on the extreme right.
3. Keep pressing an arrow key until the NUMBER line is no longer backlighted.
4. Press the right-hand key. A input mask will open.
5. Press the right-hand key Press the right-hand key until your specific code (which was "1"
on delivers) is displayed.
6. Once the required code is displayed, press the right-hand key once more to confirm the en-
try. The message "Parameters free" appears in the next line.

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You then have access to the page selection list once more.
Note:
Access to parameters and configurations is enabled for only a limited period. (90 seconds) If
more time is needed, then it will be necessary to repeat the steps needed t overcome the disa-
blement code.
7.2 Displayed values
For the calculation of lambda and dew point it is necessary to enter characteristic values as al-
so detailed under "Options".

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Here you can adjust the measured value with an set point value of a test gas by varying
“EMF+” or “EMF*”. The result is displayed under “LOG” and “O2”
The value 0.00 for the additive correction and of 1.0 for the multiplicative correction means
that no correction is to be applied to the determined EMF value.
7.3 Process parameters
This page is selected from the page list as described above. The unlighted cursor beam can be
positioned against the required value by means of the arrow keys. The cursor beam is then
positioned against the value concerned and the entry is confirmed by pressing the right-hand
key. The displayed value can be increased or decreased to cause the new required value to be
displayed. Once this is achieved, it is confirmed by pressing the right-hand key and the new
value is thus stored in the memory.
Filter = 0.0 means that no filter is active. Fluctuations in the sensor signal can be attenuated
with the aid of a filter factor.
7.4 mA outputs
The device has three analogue outputs. Output 1 is for the logarithmic oxygen value, Output 2
for the linear oxygen value and Output 3 for various optional values such as dew point or

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lambda: values for outputs 1 and 2 are thus displayed on one page and those for Output 3 on a
separate page.
The significance of LINmax values:
0,00 10
0
1 100%
-1,00 10
-
1
0,1 10%
-2,00 10
-
2
0,01 1%
-3,00 10
-
3
0,001 0,1% = 1000 ppm
-4,00 10
-
4
0,0001 0,01% = 100 ppm
-5,00 10
-
5
0,00001 0,001% = 10 ppm
It should be borne in mind that linear values always extend from 0 to LINmax and that with
logarithmic values the LOGmax value must always be greater than LOGmin.
A choice has to be made between four possibilities. The figure "W" has to be set accordingly.
End values have also to be set for 0 and for 20 mA. This is done by defining an end point
within the total physical range for 0 – 100 parts indicated in the table below, within which a
window for UPPER and LOWER limits can be established.
Lambda 0 to 100
CO 0 to 10%
Dew point -100 to 100 degrees
O2B 0 to 1000 ppm