METROTEC GSM Series User manual

Oxygen Measuring and Control Device
GSM Series
*** Version 3.0 ***
METROTEC
Systems for Measuring and Controlling Oxygen
GSM-touch

METROTEC
EC Declaration of Conformity
for
Oxygen Measuring and Controlling Device Type GSM-touch
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 the 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, 04/05/2023
Place, Date Signature
METROTEC GmbH
Heinkelstrasse 12 • 73230 Kirchheim • Germany
Phone [phone] • Fax [phone]
www.metrotec.eu • [e-mail]

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Table of Contents
1Safety Instructions........................................................................................................5
2Preface...........................................................................................................................6
3Introduction..................................................................................................................8
3.1 Measuring Principle ....................................................................................................... 8
3.2 Measuring Electronics....................................................................................................9
3.3 Sensor............................................................................................................................. 9
4General Layout...........................................................................................................10
4.1 Description of the Measuring Electronics.................................................................... 10
4.1.1 Main Display...................................................................................................................................... 10
4.1.2 Touch pad and Function buttons........................................................................................................ 10
4.1.3 Keyboard Entry.................................................................................................................................. 11
4.1.4 Special Buttons................................................................................................................................... 12
4.2 Description of Sensor................................................................................................... 12
4.3 Draft of Flow run .........................................................................................................13
5Commissioning the Device.........................................................................................14
5.1 Switching on the Measuring device............................................................................. 14
5.2 Measurement................................................................................................................ 17
5.2.1 Sample gas connection....................................................................................................................... 17
5.2.2 Flow ................................................................................................................................................... 17
5.2.3 Pump capacity.................................................................................................................................... 19
5.3 Cylinder Gases ............................................................................................................. 21
5.4 Process Gases............................................................................................................... 21
5.4.1 General .............................................................................................................................................. 21
5.4.2 Hot process gases .............................................................................................................................. 21
5.4.3 Special sample gases.......................................................................................................................... 21
5.4.4 Specific instructions........................................................................................................................... 22
5.4.5 Filter system: Structure...................................................................................................................... 22
5.5 Switching off the Measuring device ............................................................................22
5.5.1 Short-term switch-off ......................................................................................................................... 22
5.5.2 Long-term switch-off.......................................................................................................................... 22
6Selecting the Measured value....................................................................................24
6.1 O2................................................................................................................................. 24
6.2 Log O2 ......................................................................................................................... 25
6.3 Dew point..................................................................................................................... 26
6.4 Lambda......................................................................................................................... 27
6.5 O2 Red ( O2in H2 )....................................................................................................... 27
6.6 Redox ........................................................................................................................... 28
6.7 Redox Graph ................................................................................................................ 28
7Parameterization........................................................................................................30
7.1 Enabling User levels .................................................................................................... 30
7.2 Level "0" ...................................................................................................................... 33
7.2.1 General settings ................................................................................................................................. 34
7.2.2 Pump Parameters............................................................................................................................... 34

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7.2.3 Alarm History..................................................................................................................................... 34
7.3 Level "1" ...................................................................................................................... 35
7.3.1 Settings described on Level 0............................................................................................................. 35
7.3.2 Alarms................................................................................................................................................ 36
7.3.3 Analog outputs ................................................................................................................................... 39
7.3.4 Data logging ...................................................................................................................................... 41
7.3.5 Bus Parameters.................................................................................................................................. 44
7.3.6 Password............................................................................................................................................ 46
7.3.7 Diagram............................................................................................................................................. 47
7.3.8 Date & Time....................................................................................................................................... 49
7.4 Level "2" ...................................................................................................................... 50
7.4.1 Settings described on Level 1............................................................................................................. 51
7.4.2 Correction of a measured value......................................................................................................... 51
7.4.3 Gas Constants.................................................................................................................................... 53
7.4.4 Password (CODE) ............................................................................................................................. 55
7.4.5 Redox Temperature............................................................................................................................ 56
7.5 Level "3" ...................................................................................................................... 58
8Connections.................................................................................................................58
8.1 Analog inputs ............................................................................................................... 58
8.2 Analog outputs ............................................................................................................. 59
8.3 Alarm outputs...............................................................................................................59
8.4 Data bus........................................................................................................................ 60
8.5 Network........................................................................................................................ 60
8.6 USB.............................................................................................................................. 60
9Network.......................................................................................................................61
9.1 Connection to an Ethernet network.............................................................................. 61
10 Data File Examples.....................................................................................................63
10.1 Field bus RS485........................................................................................................... 63
10.1.1 Example with Putty ....................................................................................................................... 63
10.1.2 Example with HTERM................................................................................................................... 64
10.2 Modbus UDP................................................................................................................ 64
10.2.1 Example using SimplyModbus TCP .............................................................................................. 64
10.2.2 Example using METROTEC Excel-MBAXP ................................................................................. 66
10.2.3 Example using Siemens LOGO! (German version)....................................................................... 67
10.3 PLC .............................................................................................................................. 71
11 Messages in the info line ............................................................................................71
12 Interfaces.....................................................................................................................71
12.1 Analog interfaces ......................................................................................................... 71
12.2 Digital interfaces.......................................................................................................... 71
13 Technical data.............................................................................................................72

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1Safety Instructions

Please read these operating instructions carefully before installing
and using the device.
Improper use of the product will invalidate the warranty!
The ambient conditions described in the Specifications chapter must
be complied with in order to ensure the device's proper functioning
and operational safety.
The device may only be started up and operated by qualified and
trained personnel. The operator of the device must ensure that all
applicable regulations and guidelines are complied with. These are,
among others, the EU Directive on work safety, national work safety
legislation, accident prevention regulations, etc.
Please ensure that the supply corresponds with the information given
on the type plate. All coverings necessary to provide touch
protection must be installed. In case the device is interconnected
with other devices and/or installations, the consequences must be
considered and appropriate precautions taken before switching the
device on.
In some cases, hot parts or surfaces may be unprotected during or
after installing or uninstalling the device. Appropriate precautions
must be taken to avoid injuries and/or damage.
In case the device shows defects which suggest that it will not be
possible to operate it safely, it must not be put into operation. We
recommend to have the device inspected at least once a year at the
factory or by a customer service representative.
Disposal of the device must be performed according to the
applicable regulations.

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2Preface
The measuring device serves for recording oxygen partial pressures in gas atmospheres in
connection with an oxygen sensor. Such sensors operate at high temperatures. Therefore,
precautions must be taken to keep ignitable gas mixtures from reaching the sensor or the
device. In case of the sensor ceramic breaking, sample gases may leak or air may enter the
sample gas side. Should this occur, applicable measures must be provided for to protect the
environment and device parts from damage.
Wrong entries, leaks, corrosion, condensation, etc. may cause
damage of the plant and erroneous measurements. It is vital to
have all parts of the system maintained regularly.
The oxygen meters and the attachments have been
produced and controlled subject to complete quality as-
surance in accordance with DIN EN-ISO 9001.
Installation and operation must be performed subject to
compliance with all local and special regulations. These
particularly include VDE and DVGW requirements.
Depending on the application, a periodic inspection of
the measuring device in terms of measuring accuracy
and function may be required and must be performed in
the course of calibration and inspection procedures after
initial commissioning.

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3Introduction
The GSM-touch is a user-friendly measuring instrument for the detection of oxygen partial
pressures. The applied measuring principle, with a measuring span of more than 30 decades,
allows for the measuring of high concentrations to very small traces.
Therefore, integrated functions facilitate the drawing of conclusions on a variety of technical
processes in process engineering.
3.1 Measuring Principle
Oxygen measuring devices are designed to process signals received from an oxygen sensor
made of stabilized zirconium dioxide. Zirconium dioxide, a ceramic also referred to as solid
state electrolyte, is perfectly suited to serve as an oxygen-ion conductor at high temperatures.
Within a certain temperature range depending on the doping of the material, ion conductors of
this type are able to fill vacancies in their crystal lattices with oxygen ions. The oxygen ions
form itself on a conductive contact layer, which usually consists of platinum.
Thus, the oxygen concentration in a sample gas is essential for the extent of oxygen activity
and accordingly the number of oxygen ions.
The basic structure of a sensor revolves around a solid state electrolyte which is contacted on
both sides. One side of the electrolyte is operated by a reference gas, such as air, the other one
with sample gas. The mechanical structure of the sensor separates the two gas sides from each
other, so that the gases cannot mix.
Depending on the application, the sensors used are either heated or unheated. Unheated
sensors are mainly used in the area of the oven, while heated sensors are chosen for
applications in which gases with a temperature of less than 600 degrees Celsius are to be
measured. (The measuring principle requires a minimum temperature of 500 –650 degrees
Celsius.)
Heated sensors are adjusted to a certain target temperature by means of a temperature
controller integrated in the processing electronics. The temperature of heated and unheated
sensors is measured by the electronic unit and is an essential element in the calculation of the
oxygen oxygen level (oxygen partial pressure).
The value is calculated by means of the following formula:
EMK R T
FP P

 4
1
2
ln( )
whereby
R
=
8.31J/mol K
T
=
Temperature in Kelvin
F
=
96493 As/mol
P1
=
Oxygen partial pressure on the reference side with 0.20946 bar
P2
=
Oxygen partial pressure on the sample gas side
EMF
=
Electromotive force in Volt

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3.2 Measuring Electronics
The GSM-touch measuring device electronics features the following functions:
Measuring the oxygen partial pressure
Generating alarms
Calculating the dew point
Calculating the Lambda air factor
Calculating redox potentials
The measuring device is operated via a touch screen.
Inputs and outputs are preselected and parameterized by the operator via menus.
3.3 Sensor
The sensor is integrated in the measuring electronics. It consists of the measuring element
made of plated zirconium oxide, the heating required to heat up the measuring element to the
temperature allowing the measuring operation, as well as the thermocouple for the exact
recording of the temperature for the heating controller.
Note:
The heated block will grow hot during operation and warm up the housing due to its design,
particularly on the left side. Please make sure that a minimum distance of ca. 50 cm to other
objects is adhered to, so that the heat can freely dissipate from and circulate around the
device.
Preventive measures, such as controlled case fans, temperature monitoring, and deactivation
of the heating in case of excessive temperature will make sure that the housing temperature
will not reach inadmissible temperatures.
Touch Screen
Fan
Gas pump
Ethernet,
USB,
D-Sub
Handle
Mains
connection
M12 connections lower row:
analog inputs, analog outputs,
alarm outputs, bus connection,
Data logging
external USB storage

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4General Layout
4.1 Description of the Measuring Electronics
4.1.1 Main Display
4.1.2 Touch pad and Function buttons
Touch pad for selecting measured values and
measuring functions
Buttons for the general handling of the device
Info line
Button
for
defined
switch-off
Button
Menu
selection
Display of
active
Measuring outputs
Touch pad for selecting the
Measuring unit
Measuring unit
Measured value
Axis showing the
Measured values
Time
axis
Graph
Button
Gas pump
ON/OFF
Button for
Data logging
Internal/UBS

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Button opens settings and parameterization
menu.
Button switches sample gas pump ON/OFF
Button starts/stops data logging on internal
memory. (In front of "Stop" the number of
stored data records is shown)
Button starts/stops data logging on USB stick. .
(In front of "Stop" the number of stored data
records is shown)
Button activates a shutdown procedure
4.1.3 Keyboard Entry
Previous value
Currently entered
value
back
save
Entry range

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4.1.4 Special Buttons
Currently entered value is deleted
Last entry is deleted
One or more menu pages back without saving
Leave Save and Menu page
4.2 Description of Sensor
After switching on the device, the sensor will be heated up to measuring temperature within
the following 15 minutes. (Attention: Sensor will not deliver viable measured values during
this process.)
With the sample gas input open and gas pump activated, the device should display
20.9 % O2. If required, this value can be corrected. (see "Measured value correction").
After the heating up phase, the sensor is connected with the sample gas. Please note that the
maximum flow of sample gas will not exceed the display range of the flow meter. This is
particularly important when measuring a gas cylinder with excess pressure.
Exceeding the flow limit may cause disruption of the sensor

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4.3 Draft of Flow run

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5Commissioning the Device
5.1 Switching on the Measuring device
After connecting the power cable to the mains, the power switch can be activated.
The display lights up briefly. After ca. 30 seconds, system start information and, after the boot
procedure, the standard screen or the measuring instrument screen last activated will be
displayed, depending on the default setting.
As long as the sensor temperature is below the target value, the measured value is shown as
"- - - ". The info line displays the current status of the heating process on a yellow
background.
The diagram area may show a measured value independent from the heating up status.

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After the heating up phase, the measuring unit will display the measured oxygen value. In this
case the info area shows: "Ready" while the background colour is green. A stable measured
value is reached 15 minutes after the heating up process has been
completed.
The start screen may display an alarm message in the info line on a red background. The
alarm message can be removed by entering suitable alarm limits (see section "Alarms") and if
the measured value lies within these limits.
The measured value is shown independently of alarms and diagram parameters.

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The start screen may display an alarm message in the info line on a red background. The
alarm message can be removed by entering suitable alarm limits (see section "Alarms") and if
the measured value lies within these limits.
The diagram area background will turn red if the measured value is beyond the defined
diagram axis. (see section "Format Diagram").
The measured value is shown independently of alarms and diagram parameters.

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In case the beeper is activated and an alarm pending, the diagram area will display "Beeper
Off"
The button
will acknowledge the beeper and the button fades out.
5.2 Measurement
5.2.1 Sample gas connection
After the starting routine the device is ready for use and can determine the oxygen content in
gases. This requires connecting the measured medium with the sample gas port.
5.2.2 Flow
In order to examine the sample gases, they need to be supplied to the measuring instrument.
In case the sample gas source has excess pressure, such as a gas cylinder, the gas flow must
be reduced to an admissible level by means of a valve or a pressure reducer.
The maximum gas flow must not be exceeded, as otherwise the sensors will be destroyed. We
recommend a 60 - 80 % flow.
Note:
Recording the amount of gas flowing is based on a calorimetric principle. Due to the fact,
that different gases have different heat transfer properties, the particular characteristic
curves for air, argon, forming gas and hydrogen have been stored. The current selection is
displayed as text.

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The flow is shown in the touch screen. The parameterization is described separately (see
Pump parameters: Flow)
In case, the pressure of the sample gas source is too low to feed the sample gases through the
measuring instrument, the integrated sample gas pump must be switched on by pressing the
"Pump" button (see Pump parameters).
Pressing
switches on the gas pump.
As long as the
gas pump is activated,
is displayed.

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5.2.3 Pump capacity
There are two possible modes for operating the sample gas pump:
Automatic mode
In automatic mode, the capacity of the sample gas pump is
controlled. For this purpose, the current indication of the flow
meter, which is scaled to 0-100 %, will be compared with the
target value. The resulting control deviation will then adjust the
pump capacity so that the target value is observed. This should
occur independently of the conditions of the gas sampling.
Note: This specification may have to be modified to be in
accordance with the type of sample gas used. Entry can only be
made by CODE from level 1 or higher.
Manual mode
In manual mode, a specific speed is defined as target value. The
speed is scaled to 0-100 %. The sample gas pump delivers a certain
sample gas flow, depending on the length of the sample gas line
and the pressure in the sample gas line. It must be adjusted such
that the sample gas flow remains within the permissible limits.
The pump capacity can be set in the "Pump Parameter" menu.
Pressing the button
opens:
Pressing the button
opens:
Current setting are shown
here. These can be
changed by pressing the
corresponding buttons.
Note: The gas type
relevant for measuring
the flow cannot be
changed on this enabling
level.
For this example, the
operation mode

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"Automatic" has been
chosen.
The current flow as well
as the target value are
displayed.
Pressing the button
opens:
A new target value can
be entered here.
For this example, the
operation mode
"Manual" has been
chosen.
The current flow as well
as the target value are
displayed.
Pressing the button
opens:
A new value within the
range shown can be
entered here.
The set values can be verified in the overview image.