While using CO2 fertilisation in greenhouses, there is a possibility of amassment or pile up of harmful gas. The reason for this pile up is that CO2 is consumed by the crop, and harmful gas is not immediately broke down. A small amount of (harmful) gas which is present in the greenhouse for a relative short period of time, would (normally) not be detrimental for the crop. However, exposing the crop to a minimum of gas for a relative long period of time could damage the crop. This is also dependent of kind of crop, cultivar, age and improving stress conditions like light, temperature, RH etc. around the crop.
The MACView®-Greenhouse GA measures 5 types of gases at the same time which have all known effects on crop. NO (Nitric Oxide): This type of gas is most of the time submitted by combustion processes. This processes could be: engines (cogeneration), boilers, stoves, fire, motor-vans/Cars. Crop can handle a certain amount of NO. Above that amount, NO becomes toxic for the crop. The crop the waste energy to break down the toxic..
NO2 (Nitrogen Dioxide): NO2 is often produced as a result of incomplete combustion . Crop can handle a certain amount of NO2. Above that amount, NO2 becomes also toxic for the crop.
C2H4(Ethylene or Ethene): Like NO and NO2, Ethylene is also submitted by (incomplete) combustion processes. Ethylene is a well known plant hormone. Unlike to the previous gases, ethylene is also produced in nature. The crop is capable of producing a little amount of ethylene. In practice, these little amounts aren’t enough to make a clearly measurement. Ethylene at higher levels can cause premature senescence, flower abortion and unwanted colouring of leaves.
CO (Carbon Oxide): Normally CO isn’t that bad for plants. However where NO, NO2 and ethylene are produced during combustion processes, there’s also most of the time CO available which causes incomplete combustion. With this parameter it would be possible to detect the reason of air pollution in greenhouses.
CO2 (Carbon dioxide): In contrast to NOx, ethylene and CO, CO2 is the wanted component to fertilize the Crop. The ratio between harmful gas components and CO2 is thus important.
Connection to the Climate computer
The MACView®-Greenhouse GA monitors gas on the level of the crop. In this way, the climate in the greenhouse can be controlled with the gathered information. It is recommended to connect the MACView®-Greenhouse GA to a climate computer to compare for example with the CO2 dosing, running engine, opening/closing windows. This can be done in different ways. Which type of connection is the best, is to be determined in consultation. The different ways of connection are:
- Analog outputs (6 connections)
- Digital interface connection via RS485
- Remote interface via internet or database
Growers who won’t use a connection between the MACView® Greenhouse GA and a climate computer, can use the enclosed software. This software reads the Gas Analysers internal storage memory and plot those values into a graph or table.
Reasons of existing gases
As a reason of present harmful gases in greenhouses, people often blames potential polluters like cogeneration, engines and boilers. Nevertheless, because of those are well-known reasons, those systems are build with extreme care and preventive sanctions are taken. Most of the time there are unknown insidious reasons. Possible reasons of pollution are the position of the greenhouse in relation to a (high)ways, chimneys, petrol stations, mud(pits), dung hills etc. Another mindsets are the position of the air inlet, possible leaks, the use of forklifts, loading docks, terminals, the use of pulsfog etc. In principle “fresh air” coming inside by the windows could be a potential source of pollution nobody thought about.
Calibration / Maintenance
The MACView®-Greenhouse Gas Analyser is an instrument that needs to be calibrated 2 times a year. EMS performs this calibration itself. We can offer you a maintenance contract in which we provide all the maintenance and calibration.
Tests provided by WUR
The predecessor of the MACView®-Greenhouse Gas Analyser (Bulb / Postharvest Ethylene Analyser) was tested by the WUR. (“Wageningen University & Research”). The PPO flowerbulbs department and the Agrotechnology Food Sciences Group (Postharvest) department have tested this predecessor of the Gas Analyser. These tests were carried out by a comparison with a gaschromatograph. The conclusion resulted in the fact that the precision of the tested system was better then the lowest detection level (10 ppb) of the gaschromatograph. Also the WUR was looking for a quality product which can handle measurements in the ppb range and which is suitable for agricultural industry. The MACView®-Greenhouse Gas Analyser is made for high temperature locations with a high humidity, present in greenhouses. To summarise: Be aware of harmful gases for your crop, and monitor them!
|Type of Gas Analyser||MACView®-Greenhouse Gas Analyser|
|Type of Sensors||NO (Nitric Oxide) measurement range 0-2.000 ppb |
NO2 (Nitrogen Dioxide) measurement range 0-2.000 ppb
C2H4 (Ethylene) measurement range 0-2.000 ppb
CO (Carbon Oxide) measurement range 0-2.000 ppb
CO2 (Carbon Dioxide) level 0-2.000 ppm
|Resolution:||1 ppb for NO, NO2, C2H4 and 10 ppm for CO2 Minimum inaccuracy ±1% below a level of 200 ppb Maximum inaccuracy ±2% between the 200 and 5000 ppb|
|Measurement interval||4 to 6 measurements in a hour|
|Inlet / Outlet of the flow||2 inlets; sampling on 2 different levels; inlet can be elongated with a tube of 3 meter for sampling in top of the crop|
|Type of Housing||White painted stainless steel; Protection class IP54|
|(Safety / EMC) Standards||NEN-EN-IEC 61000-6 -1,-2,-3,-4; CE|
|Measurement Modus||Measure mode, Zero mode, Standby, Flushing mode (Full-automatic safety which protects the sensors against damage unwanted chemicals)|
|Settings of Detection and Alarm||Hysteresis for setting the relays , status notifications, power, failures|
|Analog Outputs||Hysteresis for setting the relays , status notifications, power, failures|
|Analog Outputs||5: Both has the possibility of: 0-20mA; 4-20mA; 0-10V|
|Data interface / service interface||Serial; 2 RS 232 interfaces and 1 RS485 interface|
|Data Storage||Internal data storage. Up to 10.000 records. Read-out software included|
|Powering||110 - 230 VAC 2.35A|
|Working Temperature||-10 ~ 45oC, Working Humidity 5 - 99% (not-condensed)|
|Software||Included, Possibility for display graphs, tables with data and time; Suitable with Windows 2000, Windows XP, Vista and Windows 7|
|Languages||English and Dutch|
|Control Panel||1 Graphic Display on GA and 1 additonal for control and read-out on long distan ce with backlight and menu|
|Dimensions||Housing: l x w x d 1560mm x 190mm x 180mm|
- Interfacing the MacView Greenhouse Gas Analyser with a climate computer, climate control system or process computer
- Effects on the crop, arguments for the use of the Greenhouse GA and application examples (English)
- Leaflet MacView Greenhouse Gas Analyser
- Concentration vs risk NOx & Ethene (Dutch)
- Effect op het gewas, argumenten voor het gebruik van de Greenhouse GA en applicatievoorbeelden (Dutch)
- Kwaliteit kaslucht cruciaal voor goede productie (Dutch)
- Leaflet MacView Greenhouse Gas Analyser (Dutch)
- Evaluation report MACView Ethylene Analyser (English)
- Presentation Hortifair 2012 (English)
- Productvel MACView-Greenhouse Gas Analyser - fruits - print version A4 (Dutch)
- Productvel MACView-Greenhouse Gas Analyser - fruits - print version A4 (English)
- L’analyseur de gaz à effet de serre MACView® - fruits - screen version (French)
- L’analyseur de gaz à effet de serre MACView® - screen version (French)
- Effets du NOx et de l’éthène sur les cultures - Description de l'application (French) V1.2