Angst+Pfister PZA Series User manual

Instruction manual
PZA-MC25 electronics unit
EC Declaration of Conformity for PZA series oxygen measurement and control device
This device is designed for industrial use in accordance with:
EN 50081-2
EN 50082-2
It complies with the following directives:
EMC Directive: 2004/108/EC
Low Voltage Directive: 2006/95/EC
Machinery Directive: 2006/42/EC
The device meets the following standards:
EN 61010-1
EN 50081-2
EN 50082-2
Description of the measures taken to ensure conformity:
Quality management system DIN EN ISO 9001:2008, No. 12 100 27736 TMS
This declaration shall cease to be valid if changes are made without our consent.
*** Version 1.1 ***
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Contents
1Safety instructions.......................4
2Preface..........................................5
3Introduction.................................6
3.1 Measuring principle.......................6
3.2 Measuring module.........................7
3.3 Sensor............................................7
4General design .............................8
4.1 Description of the measurement
electronics......................................8
5Starting up the module ...............8
5.1 Switching on the measuring
module...........................................8
5.2 Measuring......................................8
5.3 Switching off the measuring
module……. ..................................8
6Output of readings ......................9
7Configuration..............................9
7.1 Correcting readings.......................9
7.2 Setting the limit value...................9
7.3 Practical tip ................................. 10
7.4 Defining the analogue outputs....10
8Interfaces ...................................11
8.1 Analogue interfaces ....................11
8.2 Digital interfaces.........................11
9App for Android smartphones.11
10 Input explained .........................18
11 Terminal connections ...............19
12 Technical data...........................20
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1Safety instructions

Please read this instruction manual carefully before installing the
sensor & module and using it for the first time.
Improper use will void any warranty!
The correct function and operational safety of the module are
guaranteed only under the environmental conditions specified in the
‘Technical data’ section.
Only qualified and trained personnel should be permitted to start up
and operate the sensor & module. The operator of the sensor & module
must ensure that all relevant laws and directives are observed. These
include EC Directives and national legislation on workplace safety,
accident prevention regulations, etc.
Ensure that the supply voltage corresponds with the specification on
the rating plate. Make sure that all the covers required to prevent
accidental contact are fitted. If the module is to be connected to other
devices and/or equipment, consider the effects before switching the
unit on and take all necessary precautions.
Hot surfaces or components may be exposed in the course of installing
or uninstalling the sensor & module. Suitable precautions must be
taken in order to prevent injuries or damage.
If the module shows signs of damage that suggest operating it may not
be safe, do not operate the device. We recommend that the device is
inspected at our factory or by our customer service department at least
once a year.
At the end of its life, the module must be disposed of in compliance
with statutory regulations.
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2Preface
The measuring module is designed to record the partial pressure of oxygen in a gas atmosphere
in conjunction with an oxygen sensor. Sensors of this kind work at high temperatures.
Precautions should therefore be taken to prevent flammable gas mixtures reaching the sensor
or the device. If a fracture appears in the sensor ceramic, sample gases could escape or air could
permeate the sample gas. Suitable measures must be taken to prevent damage to the
environment and the equipment.
Incorrect parameters, leaks, corrosion, condensation, etc., can
damage the equipment and result in faulty readings. Regular
maintenance of all parts of the equipment is critical.
The manufacture and testing of our oxygen concentration
measurement modules and accessories are subject to
continuous quality control in accordance with ISO 9001.
They must only be installed and used in compliance with
all applicable local and special regulations. These include
the VDE and DVGW standards.
The accuracy and function of the measuring module must
be checked at regular intervals that depend on the
application. This check must form part of the calibration
and inspection procedures carried out following initial
use of the module.
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3Introduction
3.1 Measuring principle
Oxygen measuring devices are designed to process signals transmitted by an oxygen sensor
made from stabilised zirconia. Zirconia, a ceramic material that is also referred to as a solid
state electrolyte, acts as an excellent oxygen ion conductor at high temperatures.
Within certain temperature limits that depend on the doping of the material, ion conductors of
this kind are able to fill empty spaces in their crystal lattice with oxygen ions. The oxygen ions
form on a conductive contact layer that generally consists of platinum.
The concentration of oxygen in a sample gas indicates the degree of oxygen activity or, in other
words, the number of oxygen ions.
A sensor essentially consists of a solid state electrolyte with a contact surface on both sides.
One side of the electrolyte is in contact with a reference gas, such as air, and the other with the
sample gas. The mechanical structure of the sensor keeps the two sides separate, preventing the
gases from intermingling.
Heated or unheated sensors are used, depending on the application. Unheated sensors are
predominantly used in furnaces, while heated sensors are used for applications that involve
measuring gas below around 600 degrees Celsius. (Themeasuring principle dictates a minimum
temperature of 500–650 degrees.)
Heated sensors are maintained at a set temperature by a temperature regulator that forms part
of the processing electronics. The temperature of both heated and unheated sensors is measured
by the electronics and incorporated in the calculation of the oxygen content (partial pressure of
oxygen).
The calculation is based on the following equation:
EMK R T
FP P
=
 4
1
2
ln( )
whereby:
R
=
8.31J/mol K
T
=
temperature in Kelvin
F
=
96493 As/mol
P1
=
partial pressure of oxygen on the reference side with 0.20946
bar
P2
=
partial pressure of oxygen on the sample gas side
EMF
=
electromotive force in volts
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3.2 Measuring module
The PZA series measuring module features the following functions:
-Measurement of the partial pressure of oxygen in conjunction with a separate Series A
sensor. Select the PZA-MC25-N variant for diffusion-based measurements and the
PZA-MC25-P variant for flow-based measurements (see separate instruction manual for
the Series A sensors)
-Output of the reading 4 to 20 mA
-Alarm signals
Following installation, you can adjust the module’s parameters, if required. The module then
remains in continuous operation with these settings.
Please note:
If you wish to make extensive changes and display the measured readings, you will need the
PZA app for Android smartphones. The APP can be downloaded by using the QR code on the
sensor and/or electronics units
3.3 Sensor
To function, the measuring module requires a separate A-series oxygen sensor.
To connect the A-series oxygen sensor, see point 2 under ‘Terminal connections’ and the
separate instruction manual for the A-series sensor.
The chosen A-series sensor and the PZA-MC25 electronic unit are paired together in the
factory. The calibration protocol has both serial numbers printed in the protocol.
Never use non-paired sensors and electronic units. This will result in erroneous measurements.
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4General design
4.1 Description of the measurement electronics
The front of the unit is divided into different areas: the LED display, the sensor connector and
the terminal strip.
5Starting up the device
5.1 Switching on the measuring module
The wiring of the measuring module is indicated in the circuit diagram. As soon as the power
is switched on, the module is ready to start.
Once the sensor has heated up, the ‘Ready’ LED changes from red to green.
If the current reading is below the set limit, the ‘Alarm’ LED is green. If it is above the limit,
a red light indicates a combined alarm.
After the sensor has heated up, the measuring module delivers the reading to the assigned mA
output.
5.2 Measurement mode
Once switched on, the module is ready for operation and able to measure the oxygen in gases.
Depending on the type of sensor used, the sample gas either has to be fed to the sensor or the
sensor has to be placed in the sample gas. For details, see the instruction manual for the sensor.
5.3 Switching off the measuring module
It is advisable to keep the sensor & module in continuous operation. This prevents
condensation that could lead to corrosion when using heated sensors.
However, if you do need to switch off the module, you can do this by cutting the power
supply to the measuring module.
For details, see the instruction manual for the A-series sensor.
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6Output of readings
The measuring module output the reading in a linear format. The default setting is 0-25% O2
‘linear’ at 4-20 mA. Another measuring range (0-1000 ppm O2) can be activated using a
terminal connection jumper.You can switch measuring ranges automatically via a potential-
free contact.
Please note:
The assignment is fixed and can only be changed locally using a smartphone app.
7Configuration
The configuration can be changed locally.
Please note:
If you wish to make extensive changes and display the measured readings, you will need the
PZA app for Android smartphones.
7.1 Correcting readings
If necessary, you can correct the current reading. We advise that you only do this if the
reading is stable and you have ruled out the possibility of other measuring errors.
The reading can only be adjusted using the PZA app for Android smartphones.
7.2 Setting the limit value
The alarm is activated if the current reading falls below the set threshold. As a rule, the limit
value will be within the programmed measuring range. An alarm status is signalled by the
Alarm LED.
At the same time, the semiconductor relay that contacts terminals Alarm and Alarm in the
terminal connection is activated.
The limit value can only be changed using the PZA app for Android smartphones.
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7.3 Practical tip
It is often the case that the mA signal is not displayed within comfortable viewing distance of
the measuring module. We therefore suggest that you temporarily remove the connections
from the ‘-mA’ and ‘+mA’ terminals and connect up a standard portable mA multimeter
instead.
You can now make any checks and adjustments you need. After completing the settings,
restore your previous connections.
7.4 Defining the analogue outputs
The two measuring ranges for analogue output can be switched using a jumper between
terminals ‘Switch’ and ‘Switch’. Or you can switch measuring ranges automatically via a
potential-free contact.
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8Interfaces
8.1 Analogue interfaces
There is one 4-20 mA analogue interface.
8.2 Digital interfaces
Semiconductor relay for combined alarm
9App for Android smartphones
The app allows you to view readings and change configuration settings. First, the measuring
module and the smartphone have to be paired via Bluetooth. We recommend how to do this
below. However, the procedure may differ slightly with some smartphones.
Image: Example of pairing.
The passkey required is ‘1234’. After entering the passkey, a connection is established
between the measuring device and the smartphone.
1. Switch off the power to the measuring module.
2. Switch on the power to the measuring module. The ‘BT’ LED flashes.
Please note: Pairing must be completed within 60 seconds of switching on the power
supply. The process can then be repeated.
The following image shows an example of a pairing passkey that is entered in the
smartphone menu and activated.
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3. Following pairing, the app can be activated on the smartphone.
4. Select the Bluetooth module.
The app now launches. To open a message, click on the icon shown on the right.
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5. The following display opens.
6. After clicking on ‘Connect’, you will be prompted to choose a device.
7. Select the correct device.
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8. Communication begins after a few seconds and all of the parameters are transferred.
9. The app display shows the current values for Reference Point, Operating Point and
Limit Value. You CANNOT make any changes here.
The ‘BT’ LED on the device lights up in green.
10. To enable parameter changes, click on the arrow icon shown in the centre of the image
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Then press ‘Remote enable’.
11. After entering the PIN ‘5678’, parameter changes are enabled.
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12. The following display appears:
The display is now much more brightly lit.
ATTENTION! The Reference Point, Operating Point, and Limit Value can now be
adjusted. Changing the ‘Reference Point’ and ‘Operating Point’ affects the reading
currently displayed and the reading output.
We recommend that you read the ‘Input explained’ section before making the
adjustments.
13. If you need to make further changes or see further information, you can call up an
additional menu. To do this, click on the icon on the right of the image and then on
‘More’. The following pop-up appears:
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If you now select ‘Settings’, a menu appears:
Details of what the various items in this list mean can be found in the ‘Input
explained’ section.
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10 Input explained
Menu
Explanation
Action
0
Current oxygen reading
Cannot be changed
1
Current temperature reading
Cannot be changed
2
Correction for air flushing
Sensor must be at operating temperature and flushed with clean air. The
value is corrected until menu item 9 shows zero millivolts
Can be changed
3
Correction for test gas
Sensor must be at operating temperature and flushed with test gas. Menu
item 2 should precede this stage. The value is corrected until menu item 0
shows the required value.
Can be changed
4
Reading output for 0/4 mA in ppm
Can be changed
5
Reading output for 20 mA in ppm
Can be changed
6
Limit value for alarm in ppm
Can be changed
7
Display for alarm, 0/4-20 mA
Cannot be changed
9
Display for sensor signal in mV
Cannot be changed
10
Display of output value in mA
Cannot be changed
12
Reading output for 0/4 mA in ppm for 2nd measuring range
Can be changed
13
Reading output for 20 mA in ppm for 2nd measuring range
Can be changed
14
Hysteresis for alarm relay in ppm
Can be changed
64
Cable length
Can be changed
80
Display of output status
Cannot be changed
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11 Terminal connections
Terminal
Designation
Explanation
24 VDC
+ 24 VDC
Power
0 VDC
- (GND)
Power
+mA
mA+
Reading output +
- mA
mA-
Reading output -
Alarm
Alarm relay
Combined alarm
Alarm
Alarm relay
Combined alarm
Switch
Jumper to Switch terminal
Switch measuring range 1 to measuring range 2
Switch
Jumper to Switch terminal
9
Test for service
10
Test for service
Please note:
Digital outputs are potential-free semiconductor contacts (1 A, 24 V), mA output is isolated.
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12 Technical data
Measuring range
25% to 1 ppmO2
Ambient temperature
0 to 45 degrees Celsius
Accuracy
+/- 0.3 mV of the sensor EMF
+/- 2 degrees Celsius
+/- 2% of mA output
+/- 2% of the log partial pressure of oxygen
Dimensions
approx. 40 x 130 x 120 mm (h x w x d)
Weight
0.5 kg
Electromagnetic compatibility
The device complies with European Directive
89/336EEC. It meets the following generic
standards: Emitted interference EN 50081-1
Interference immunity EN 50082-2. The
device can be used without restrictions in
domestic and industrial settings.
Mains voltage
24 VDC - note ! Incorrect voltage may cause
permanent damage to the module!
Performance
Depends on sensor type, max. approx. 100
VA
Analogue output
4 –20 mA potential-free
Relay output
For combined alarm, 1 A, 24 V (ohmic)
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