cairnet gprs v2 - networkcairpol.com/wp-content/uploads/2017/04/p092b.abd...miniature air monitoring...

MINIATURE AIR MONITORING SYSTEMS

Ref : P092B.ABD.CAIRNETGPRS-V2-UserGuide.210316-EN

Office : CAIRPOL Tél : +33 (0)4 73 84 46 44

ZA La Novialle Fax : +33 (0)4 73 84 40 06

10, rue de la Serre [email protected]

63670 LA ROCHE BLANCHE - France site : www.cairpol.com

SARL au capital de 354 200€ - N° Siren : 492 976 253

CAIRNET GPRS V2 - NETWORK USER’S GUIDE








CONTENTS

1. EQUIPMENT PROVIDED ______________________________________________________________ 3

2. DESCRIPTION OF THE CAIRNET GPRS NETWORK __________________________________________ 4

2.1 General description ____________________________________________________________________ 4

2.2 Brief description and principle of operation of the equipment __________________________________ 4

2.3 Principles of implementation of the network ________________________________________________ 5

3 Precautions of use __________________________________________________________________ 5

3.1 Power supply source ___________________________________________________________________ 5

3.2 Electrical precautions ___________________________________________________________________ 6

3.3 Environmental conditions _______________________________________________________________ 6

3.4 Size and Weight _______________________________________________________________________ 6

4 TECHNICAL CHARACTERISTICS _________________________________________________________ 7

4.1 General information ___________________________________________________________________ 7

4.2 Technical characteristics of the Cairnet GPRS housing and of the solar panel ______________________ 8

4.3 Technical characteristics of the communication system _______________________________________ 8

4.4 Technical characteristics of the sensors Cairsens _____________________________________________ 9

5 START-UP AND DEPLOYEMENT OF THE CAIRNET GPRS NETWORK ___________________________ 16

5.1 Start-up _____________________________________________________________________________ 16

5.2 Precautions__________________________________________________________________________ 18








1. EQUIPMENT PROVIDED

X CAIRNET GPRS set, each including :

One protective housing including the battery and the GPRS communication module, factory configured.

One solar panel fixed to its support with its mounting.

One M2M SIM card for GPRS DATA included in the GPRS communication module, previously provided by the customer and factory configured.

One to four sensors [Cairsens UART], depending of the order.

One software set :

FTP site, factory configured.

One configured PC (optional).

One CAIRMAP software suite on CD (factory installed and configured according to request), including CAIRMAP, CairGPRS and Oracle Database.

Documentation :

One user manual (installation and operating).








2. DESCRIPTION OF THE CAIRNET GPRS NETWORK

2.1 General description

The Cairnet GPRS housing is designed to create a network of remote measurement points for diffuse emissions of odorous gases, autonomous in energy and in data transmission management. The measurement and monitoring of odorous gases concentration is made on a continuous basis by our sensors, Cairsens. The measuring principle of the Cairsens is based on the use of an electrochemical sensor associated with hardware and software system to control humidity and temperature variations, paired with a regular and permanent ambient air sampling. The addition of all these components allows a precise and reliable measurement of the air surrounding the Cairnet. The Cairnet network allows:

Continuous monitoring of a given pollutant concentration at odors source, with supervision of each point of measurement of the mesh network. Each Cairnet can contain up to 3 different sensors.

Through the CAIRMAP software suite, the operator has a total access to the real-time monitoring of the measures of all sensors via a map display or more classic tables and graphs, with a complete history since the network implementation.

Through optional modules, local and remote management is made possible by the generation of daily, monthly and annual reports (with customizable indicators) which can be automatically sent (email, fax, etc.) and trigger alarms (SMS, email, etc.) after thresholds overruns, automatic export to air quality modelling systems, etc.

For the end-user, the Cairnet GPRS network gives the possibility to anticipate and monitor its odorous gases emissions, adjust its process consequently or communicate towards its neighborhood.

2.2 Brief description and principle of operation of the equipment

The Cairsens is a gas concentration indicator (fitting with the requirements of the European Directive 2008/50/EC). It can compose a network thanks to its integration in Cairnet GPRS which is autonomous in energy (thanks to its rechargeable high capacity batteries and solar panel) but also in data transmission. It can be used in indoor and/or outdoor environment, it doesn’t require any further configuration after the initial factory set-up. The GPRS communication system use the basic telephone network available almost all around the world to transfer the data collected by the Cairsens to a central PC, via an FTP site which acts as a gateway. It is used by the Cairnet as a first step to read and retrieve their settings needed for their self-operation and then in a second time to drop off sensors data files (coded and secure formats). Using the GPRS network gives to the Cairnet network a complete independency, except from the network coverage by local operators.








On the central PC, the CAIRMAP software suite reach to this data and integrate it into its database. Once the initial configuration has been made (generally in factory), it takes care at first to update the configuration settings of the Cairnet, then retrieves the data files dropped here by the Cairnet and injects them to the CAIRMAP.

The CAIRMAP gives then access to the data collected: gas concentrations (in ppb or ppm, depending of the species) at a 1 minute frequency, a new batch being injected every 10 minutes (standard). One requirement is that the central PC has Internet access.

2.3 Principles of implementation of the network

To get the network started:

Installation and start-up of the PC (pre-configured at the factory).

Launch the CAIRMAP software.

Switch ON the Cairnet (pre-configured at the factory).

Deployment of the Cairnet on their support at the chosen locations

Checking of the operational data transmission of the various Cairnet GPRS via the CAIRMAP HMI

When the network is installed and ready to be used, a period of conditioning is required for the Cairsens electrochemical cells before any use of the data (approx. 24 hours).

3 Precautions of use

Please read this chapter before any installation to avoid any deterioration or malfunction of the equipment.

CAIRPOL technical support may be contacted during the installation:

CAIRPOL – Technical Support +33(0)4 73 84 46 44

3.1 Power supply source

The Cairnet GPRS incorporates a battery which allows it to be fully autonomous 5 to 6 days without any recharging. The battery is a LIION battery 3.7V - 19 200 mAh (short-circuit and overvoltage protection included) The Cairnet GPRS has a power connector, accessible from its base. This connector is to be connected to a power supply source or a battery charging source (mains charger or solar panel, provided with the network according to order) 2 types of power supply source and battery charging source can be used depending on the use:








Operating mode Solar Panel External power supply

Indoor or outdoor 13.5W

VCO = 10.5V - ICC = 1600 mA Converter (90 ~ 264VAC - 47 ~ 67 Hz) to 12 VDC - 1 .5A)

Overload protection and overvoltage

The user must ensure that the power supply is always active and functional. The use of a Solar Panel requires regular maintenance by the user: cleaning of the active surface with a soft and wet cloth. The use of the Cairnet in a corrosive and saline ambient environment (marine air) or near any source of corrosion (output emission of ammonia and chlorine) is not recommended, as it would affect directly the operating functions of both the Cairsens and the Cairnet.

3.2 Electrical precautions

The installation and use of the Cairnet does not require any additional specific precautions than classic precautions.

3.3 Environmental conditions

The following conditions must be respected:

Temperature: -10 ° C to 50 ° C.

Maximum relative humidity (RH %): 10% to 90%.

3.4 Size and Weight

Cairnet Box Solar panels With its fixing set

Size (cm) 37 x 23 x 20 80 x 41 x 10

Weight (Kg) 5.100 4.90








4 TECHNICAL CHARACTERISTICS 4.1 General information

The Cairnet GPRS is a tool for measuring gas concentration in the ambient air. It consists of a wireless communication system (GPRS) for the real time transmission of the sensors (Cairsens) measurements to a central PC.

Data are stored in the internal datalogger of the sensor (Cairsens) and the database of the central PC. The software (CAIRMAP + CairGPRS + Oracle Database) then allows to display and manage the data using various features.

Figure 1: The operating principle of the Cairnet GPRS network

As a reminder, the Cairnet GPRS network consists of:

X CAIRNET GPRS set, each including :

One protective housing including the battery and the GPRS communication module, factory configured

One solar panel fixed to its support with its mounting.

One M2M SIM card for GPRS DATA included in the GPRS communication module, previously provided by the customer and factory configured.

One to three sensors [Cairsens UART], depending of the order.








One software set :

FTP site, factory configured.

One configured PC (optional).

One CAIRMAP software suite on CD (factory installed and configured according to request), including CAIRMAP, CairGPRS and Oracle Database.

4.2 Technical characteristics of the Cairnet GPRS housing and of the solar panel

Enclosure and door are GFK polyester not saturated and charged with fiberglass. The door feature a molded sealing joint all, around. It is usually installed on supports which consists of stainless steel tubes, either straight vertical or angled. The solar panel is fixed on the same supports as Cairnet or other support.

The solar panel is adjustable from 0 to 90 ° with regards to the vertical line. Horizontal adjustments are possible by its rotation on its support. The solar panel is then easy to connect to the Cairnet GPRS through a plug-in connector.

4.3 Technical characteristics of the communication system

The data transmission of the Cairnet GPRS is done at an adjustable frequency (from 1 minute to 30 minutes). The central PC then reaches to this data through an internet connection to the FTP site (no wire connection between the Cairnet GPRS and the PC). The characteristics of the GPRS modules are:

GPRS module SAGEMCOM HiLoNC V2.

Frequency bands GSM 850 - EGS 900 - DCS 1800 - PCS 1900.

Emission power: Class 4 (2W) for GSM 850 - EGS 900.

Class 1 (1W) for DCS 1800 - PCS 1900.

Service of DATA supported: GPRS - CSD – Fax.

Operating temperature: -20 ° C to 80 ° C.

Antenna GSM / GPRS QUAD BAND: 850/900/1800/1900 MHz frequency band.








4.4 Technical characteristics of the sensors Cairsens

The measuring principle of our Cairsens is based on an electrochemical cell sensitive to the gas to be measured. The very low concentration measurement becomes possible by adding to this cell:

A constant and dynamic air sample.

A patented treatment system (hardware and software) of the signal.

A patented filter to smooth up humidity variations.

Working Principle of an Electrochemical Sensor

Electrochemical sensors operate by reacting with the gas of interest and producing an electrical signal proportional to the gas concentration. A typical electrochemical sensor consists of a sensing electrode and a counter electrode separated by a thin layer of electrolyte. Gas that comes in contact with the sensor first passes through a small capillary-type opening and then diffuses through a hydrophobic barrier, and eventually reaches the electrode surface. This approach is adopted to allow the proper amount of gas to react at the sensing electrode to produce a sufficient electrical signal while preventing the electrolyte from leaking out of the sensor.

The gas that diffuses through the barrier reacts at the surface of the sensing electrode involving either an oxidation or reduction mechanism. These reactions are catalyzed by the electrode materials specifically developed for the gas of interest. With a resistor connected across the electrodes, a current proportional to the gas concentration flows between the anode and the cathode. The current can be measured to determine the gas concentration. Because a current is generated in the process, the electrochemical sensor is often described as an amperometric gas sensor or a micro fuel cell. A sensor requiring an external driving voltage, it is important to have a stable and constant potential at the sensing electrode. In reality, the sensing electrode potential does not remain constant due to the continuous electrochemical reaction taking place on the surface of the electrode.

It causes deterioration of the performance of the sensor over extended periods of time. To improve the performance of the sensor, a reference electrode is introduced. This reference electrode is placed within the electrolyte in close proximity to the sensing electrode. A fixed stable constant potential is applied to the sensing electrode. The reference electrode maintains the value of this fixed voltage at the sensing electrode. No current flows to or from the reference electrode. The gas molecules react at the sensing electrode and the current flow between the sensing and the counter electrode is measured and

Figure 1: Typical Electrochemical Sensor setup

Figure 2: Hydrophobic membrane prevents liquid electrolyte from leaking out








is typically related directly to the gas concentration. The value of the voltage applied to the sensing electrode makes the sensor specific to the target gas. The micro fuel cell-type electrochemical sensors do not require an external driving voltage. For example, an electrochemical sensor specific to oxygen has an anode, either Pb or Cd, that supplies electrons for the reduction of oxygen at the cathode. During the oxidation of the anode, the electrons are released which then travel via an external circuit to the cathode where oxygen molecules consume the electrons as follows:

In acidic electrolyte:

Oxidation at the anode: 2Pb + 2H2O ® 2PbO + 4H+ + 4e- Reduction at the cathode: O2 + 4H+ + 4e- ® 2H2O

In basic electrolyte

Oxidation at the anode: 2Pb + 4OH- ® 2PbO + 2H2O + 4e- Reduction at the cathode: O2 + 2H2O + 4e- ® 4OH

All three electrodes are connected internally through the electrolyte. The electrolyte can be modelled simply as a resistor. Each electrode can be modelled simply as a large capacitor. The electrodes also have a small resistive component, but this is included as part of the electrolyte resistance.

The working electrode responds to the target gas, either oxidizing or reducing the gas, creating a current flow that is proportional to the gas concentration. This current must be supplied to the sensor through the counter electrode.

The reference electrode is used by the potentiostatic circuit to maintain a fixed potential at the working electrode. The working electrode potential must be maintained at the same potential as the reference electrode potential for unbiased sensors, or with an offset for sensors that require biasing.

The counter electrode completes the circuit with the working electrode, reducing some chemical species (normally oxygen) if the working electrode is oxidizing, or oxidizing if the working electrode is reducing the target gas. The potential of the counter electrode is allowed to float, sometimes changing as the gas concentration increases. The potential on the counter electrode is not important, so long as the potentiostat circuit can provide sufficient voltage and current to maintain the working electrode at the same potential as the reference electrode.

Figure 3: Typical Electrochemical Sensor mounted








Working Principle of photo-ionization detector (PID) A typical PID block diagram is shown in Figure 1. Molecules of interest (1) are being exposed to high-energy Vacuum Ultra Violet (VUV) radiation (2), generated by the gas discharge lamp (3). As a result, some percentage of these molecules is being ionized, i.e. converted into positively charged ions and negatively charged electrons according to the following equation:

M + photon --> M+ + e- To be ionized, the molecule M should have its Ionization Potential (IP) smaller than the energy of UV lamp photons (E). As a rule, the bigger the difference is between E an IP, the larger the detector’s response. Both E and IP are usually measured in electron-volts (eV). The Photoionization Potentials are available below. PID lamps are typically available with nominal photon energies between 8.3 and 11.7 eV. Our sensor is equipped with a 10.6 eV lamp. The pair of electrodes (4, 5) is located in the ionization volume near the lamp window. The polarizing electrode (4) is connected to the High Voltage DC source (7), the signal electrode (5) is attached to the amplifier (6) input. The electric field, created by these two electrodes, forces both electrons and ions to drift towards their respective electrode, creating a small current. This current is amplified by the amplifier chip and the output analog signal is recorded and/or displayed in digital or analog format. The output signal is proportional to the concentration of ionizable molecules in detector’s chamber and thus serves as a measure of concentration. Major air components (N2, O2, CO2) have ionization potentials greater than the UV lamp and therefore are not detected. For this reason, PID is very useful for detection of a wide range of VOCs (Volatile Organic Compounds) in ambient air, down to the low-ppb concentrations, without interference from air components. The gaseous sample is typically being delivered to the detector chamber either by pump, or by a diffusion process.

Figure 4: PID diagram








Table 1: PID ionization potentials








5 START-UP AND DEPLOYEMENT OF THE CAIRNET GPRS NETWORK 5.1 Start-up

When receiving the network, the Cairnet GPRS is turned off and the battery is 100% charged. It is recommended to keep it turned off when it is not used (in storage) or when it is out of reach of the GPRS telephone network.

The user has to set up the Cairnet in a place where access quality to the telephone network is stable and good, otherwise the quality of the service and the autonomy of the system will be affected (a prolonged search for the network is energy-consuming).

Installation example

Principle of assembling on the support

Figure 5: Principle of assembling on the support

Solar panel Fixation

Solar Panels output connector

Cairsens sensors are inside of the

box

Solar Panels

input connector








Figure 6: View of the assembly on a support

To optimize the ability to recharge of the Cairnet GPRS, it is strongly recommended to orient the solar panel due south for countries in the North of the equator and due north for countries in the South of the equator. The recommended orientations of the solar panel are:

From April to October: Angle 25° .

From October to April: Angle 45 °.








Minimum requirements of sun exposure for solar panel charging feature of the Cairnet GPRS:

Solar power on the solar panel surface has to average 340 W / m2 (Irradiance G).

Minimum daily period of sunshine: 5 hours.

To obtain the best efficiency and optimize the orientation of the solar panel, it is recommended to verify the optimum parameters of irradiance for the monitored site on the following website: http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php If this conditions are not met, the autonomy of the Cairnet can be degraded and losses of data can occur.

5.2 Precautions

The free movement of air around the Cairnet GPRS when mounted on its support must be verified. The GPRS antenna on top of the Cairnet GPRS must be oriented towards the sky and clear (example: it

must not be in contact with a roof/wall).

The connector and the fan of the Cairsens must be pointing downwards (opened side of the Cairnet GPRS). The sensor is positioned in its socket so both its air outputs on the sides aren’t obstructed. White protection cape of the Cairnet GPRS must be correctly placed on top. The solar panel is connected to the Cairnet GPRS via the available plug-in connector.

We recommend to do those checks before the Cairnet GPRS network can be considered operational. The measurement will start automatically and the data collected are then sent through GPRS and accessible through the CAIRMAP HMI on the central PC.

http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php

cairnet gprs v2 - networkcairpol.com/wp-content/uploads/2017/04/p092b.abd...miniature air monitoring...

Documents