Tag Archives: Measurement

Business Case, Humidity, News, Process, Sensors, Temperature

INDUSTRY 4.0 MONITORING FOR AUTOMOTIVE TESTING

September 19, 2019 rotronicuk Leave a comment

In 2018 the UK automotive sector was valued at £82 billion and employed 823,000 people.

As the trends towards automated, low carbon and electrical vehicles increase the requirements of modern testing and certification are critical. In this customer application we explore how one of the UK’s largest automotive test companies is meeting these new challenges helped by the adoption of the cutting edge Rotronic Monitoring System (RMS).

Automotive Test and Validation

In 2017 the Worldwide Harmonised Light Vehicle Test Procedure (WLTP) was introduced. This lab test required the assessment of fuel consumption as well as CO2 and pollutant emissions from cars during
• Test cycles based on real-driving data
• Test cycles based on a variety of driving phases
• Test cycles using both heaviest and lightest power-train configurations

Facilities that provide these tests and have access to suitable test tracks are increasingly in high demand. Prior to testing cars must be preconditioned at specific environmental
conditions and during lab testing these conditions are replicated.

The Application

In order to meet ongoing quality demands and compliance to the latest Vehicle Emissions Regulations (WLTP), our client required a solution to improve and enhance their monitoring capability in several key test areas. Latest standards required more frequent ambient measurements as well as five-minute rolling averages. Engine testing is undertaken in multiple soaking areas operating at different temperatures, ranging from -20 °C to +50 °C, requiring numerous temperature and humidity sensors monitoring different parts and areas of the test vehicles.

The Challenge
It is no longer practical to use a range of different monitoring platforms for every specific application. For the automotive industry the growth of the latest 5G and electric car technology provides new validation and testing challenges, a monitoring platform must be able to adapt to meet these new requirements easily. For our client the system had to be centrally managed with all data accessible from anywhere on site. Reporting, alarming and a clear audit trail were vital. Already having experience with a range of hardware and software it was clear that the system had to utilise standard IT infrastructure and software platforms.

Hardware Integration and Standardisation

Investing in a monitoring system traditionally locked customers in to one supplier. Where possible, RMS has been designed to support Industry 4.0 open integration and interoperability. As such, RMS software is built as a standard web service. All data sits on a standard SQL database. Industrial device interoperability is never easy, RMS provides
options via simple APIs for many applications and analogue input modules for existing analogue hardware. When a robust and secure integration solution for digital hardware is required it can be professionally integrated using our RMS-Convertor module.

The result is that end users can add supported 3rd party devices with a few clicks. These devices benefit from secure data backup and auto-recovery of data in the event of any system downtime, as well as all the normal charting, reporting and alarming features RMS offers.

Project Overview

Our client engineers favoured Red Lion E3 modules, a proven industrial I/O device from Red Lion Controls. The E3 range includes 16 channel thermocouple devices, ideal for automotive testing. Integration was achieved in partnership with Rotronic R&D. Using a trial Red Lion E3 device Rotronic was able to fully integrate the unit. Final testing was undertaken by the client to confirm that the devices performed as required.

A key feature was that the Red Lion E3 modules have the ability to daisy chain Ethernet devices. Therefore, using a single port the 16x channel Red Lion module was networked along with a high accuracy humidity and temperature RMS LAN logger to every engine test cell providing a robust, elegant solution for this industrial application.

Product Focus – Rotronic Monitoring System (RMS)

High accuracy and high frequency multi parameter monitoring including temperature, humidity, pressure and dew point.
• On premise or cloud software solution
• Support for wired and wireless data loggers
• No local end user software required just a web-browser
• Full historic record and summary reporting
• High accuracy and high frequency ambient temperature and humidity monitoring
• Ability to calculate and record 5 minute rolling averages with alarms
• Extensive support for 3rd party devices and data streams

Read the case study from Red Lion on this project here; https://www.redlion.net/resources/millbrook-technology-park-case-study

Dr Jeremy Wingate
Rotronic

Calibration, Humidity, News, Temperature

Why do we need Warehouse Mapping?

July 20, 2016 rotronicuk Leave a comment

Rotronic is proud to be able to offer an increasing range of products and services to meet the demands of our customers. The requirements for mapping especially thermal mapping are increasing dramatically in food, pharma and cosmetics production and transport industries.

But what is Thermal Mapping?
Mapping is the process of determining the temperature and often humidity gradients within a defined space. It is a vital process when the product is regulated by government agencies such as the US Food & Drug Administration (FDA) or the European Medicines Agency (EMA). Regulated materials must not exceed strict storage conditions. Fixed limits will typically exist for humidity and temperature both in terms of the absolute value and also the allowable rates of change. Mapping serves as a baseline for proving compliance within the storage spaces.

The reason for increasing regulatory compliance is to ensure products do not spoil or otherwise degrade during production, storage and transport. Warehouses are notorious for having warm or cold spots that are outside of the regular control specification. A proper mapping study serves to locate these spots and either modify or avoid the problem area. Similar problems can occur during transportation so increasingly transport is at least monitored if not fully controlled and mapped.

At 4.3 million square feet, the largest warehouse in the world is the Boeing Everett factory in Everett, WA USA. It was originally designed to construct the Boeing 747.

An FDA Form 483 is issued to a company’s management at the conclusion of an inspection when an investigator(s) has observed any conditions that in their judgement may constitute violations of the Food Drug and Cosmetic (FD&C) Act and related Acts.

Mapping in General
A mapping strategy is needed for several reasons. It is important for regulators or quality managers to understand the philosophy employed for the mapping. A documented strategy will decrease questions from any regulators reviewing your mapping study. The strategy document also helps them understand the data that is produced by the mapping process. The document acts as a tool for collaboration as other people may suggest ideas that will make your study produce better data or make your effort more efficient.

As the mapping study progresses from start to finish, the strategy document acts as your reference guide, ensuring you remain true to the agreed upon process and do not make changes that will negatively affect the study. A typical strategy is usually comprised of a few written paragraphs that includes a description of the warehouse space, the type of equipment used, the number of sensors to be used, a general idea of the sensor placement, and the duration of the study. It is not unusual for the mapping strategy to change as it evolves. Writing a detailed document at the early stages of the project may cause re-writes that can increase the total length of the project. It is usually more efficient to fully document the warehouse mapping project after the strategy is agreed. Think of the strategy document as a proposal for your mapping team or the approval team so they can buy into and understand your mapping strategy. It may also facilitate the final approval stage, later in the project, because the auditor already understands the warehouse mapping project.

Continuous Monitoring After the Warehouse Mapping
Continuous monitoring is a best practice within controlled and regulated spaces. The mapping study will determine the hot and cold zones for “worst case” sensor placement. These worst case locations should be considered when installing a permanent, continuous monitoring system. The number of sensors used for a permanent system will be far fewer than what is required for the mapping study. In some cases, continuous monitoring may require only a few sensors once the problem areas have been determined through the mapping study. A continuous monitoring system offers peace of mind as product components, manufacturing space, or storage space are maintained and on record as meeting specified environmental conditions.

If you have any queries regarding warehouse mapping feel to get in touch and we will be happy to discuss!

Dr Jeremy Wingate
Rotronic UK

CO2, Humidity, Process, Sensors, Temperature

Energy Efficiency and Indoor Air Quality

December 1, 2015 rotronicuk 1 Comment

Some of the key factors for improving energy efficiency in relation to indoor applications are the control of Relative Humidity (RH) and temperature. The question is, how to control RH to acceptable levels in an energy efficient manner. Energy efficient humidity control has a very strong bearing on thermal comfort, Indoor Air Quality (IAQ) and eventually on the health and performance of occupants in air-conditioned buildings.

Passivhaus buildings are built to a voluntary standard to improve energy efficiency and reduce ecological footprint.

IAQ control seeks to reduce Volatile Organic Compounds (VOCs), and other air impurities such as microbial contaminants. As such it is important to control relative humidity which can be a key factor leading to mould growth and the presence of bacteria and viruses, dust mites and other such organisms.

Buildings rely on a properly designed ventilation system to provide an adequate supply of cleaner air from outdoors or filtered and recirculated air

Buildings may rely on dehumidifiers like the one above to reduce RH levels to a comfortable range

Air-conditioning systems typically employ a high level of air recirculation to save energy during cooling and dehumidification. Typically recirculation rates are around 80-90%, but can sometimes be even higher. The challenge is not so much in dehumidification, but in doing so without having to overcool. As such, ventilation is integrated for general comfort and economical saving.

Rooms are often designed with specific conditions in mind including temperature, humidity, brightness, noise, and air flow. Careful engineering and implementation of building automation and control is the only way to ensure energy efficiency and building operation conditions are met during occupancy, at the lowest possible costs.

IAQ Facts:

Energy Efficiency (EE) refers to either the reduction of energy inputs for a given service or the enhancement of a service for a given amount of energy inputs.

Relative humidity is highly temperature dependent, so if the temperature is stable, it is much easier to achieve a stable RH.

Air in our atmosphere is a mixture of gases with very large distances between molecules. Therefore, air can accommodate a large quantity of water vapor. The warmer the air, the more water vapor can be accommodated.

Why the need to measure, temperature and relative humidity?

Precise temperature control of air which is supplied to a room results in maximum comfort for the occupants. The temperature should be held constantly at a particular set point to achieve this comfort.

Readings from temperature transmitters installed in the air supply duct are compared to readings inside a particular room. It is easiest to achieve a constant room temperature if there is little difference between the two values. Air temperature control in supply ducts can be employed in rooms in which the air handling unit is used mainly for the renewal of air.

Rotronic manufactures temperature and humidity transmitters such as the one above which are suitable for use in spaces where appearance is a factor.

It is with good RH control that we can process the air for air conditioned rooms independent of the state of outside air and the processes taking place in the room. This way the RH remains constant or within the preset limits and thus energy consumption for humidification and dehumidification is minimized.

Air conditioning is supposed to maintain room temperature and RH as precisely as possible through the use of systems which monitor and control temperature and humidity in the room (or in the air supply ducts to the room). Systems must be dynamic to manage the changing room air quality depending on the occupants and usage.

With precise measurement and control of temperature and humidity, energy consumption for humidification & dehumidification as well as heating and cooling can be reduced leading to energy efficient building operation with lower energy costs and healthier occupants.

Phil Robinson
Rotronic UK

CO2

CO2 in Garages and Tunnels.

September 22, 2015 rotronicuk Leave a comment

Modern vehicle engines emit many harmful substances, including carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx), hydrocarbons and some 20 other gases. It is known that all engines produce CO, particularly at cold start. To protect ourselves from this toxic gas, vehicles are installed with catalytic converters. This means that a warm running modern engine with converter generates 140 times more CO2 than CO.

Catalytic converters convert a lot of the CO produced by an engine into CO2.

Facts and Figures

The longest tunnel in Switzerland will be the Gotthard Base Tunnel (under construction) that will be 57km long. The tunnel is a railway tunnel.

The longest car tunnel in the world is located in Norway, the Laerdal tunnel, 24km.

The LEP tunnel in Cern, Switzerland/France is a 26km circular ring.

Why the need to measure CO2?

Old vehicles (pre-catalyst) generate a lot of carbon monoxide pollution, to solve this, modern vehicles were installed with catalytic converters. Catalytic converters are not very efficient during cold start up but once warm they can convert CO to CO2 very effectively. This means modern engines emit much higher quantities of CO2 than CO. It is well-known that CO is extremely toxic but CO2 in high levels can also be hazardous to health. To ensure healthy air quality it is important to provide excellent ventilation in garages and tunnels, however running a ventilation system constantly is inefficient especially when few cars are running at a time.

Levels of CO2 in large indoor car parks can become extremely dangerous if not properly controlled.

In garages and tunnels vehicles can be operating in both warm and cold conditions, therefore it is important to measure both CO and CO2 to ensure a safe environment. Today there are laws around the measuring of CO – the maximum allowed value is 35 ppm. There are however, currently no rules on measuring CO2 but this is equally as important.

How does it work?

A meter can both control and alarm locally, as well as being part of a larger complete system. This application is similar, for example, to the ventilation requirements in a classroom.

The ventilation need depends on the number of cars running in a garage or tunnel instead of the number of students in a classroom. The sensors usually used to measure CO2 and CO in public garages and tunnels are capable of covering an area of around 250 m2.

Reduced Costs

A study was made in a garage containing 77 parking places and covering an area of 1,445 m2. The study showed that using sensors to control the ventilation reduced the fan operating time by 90% compared to constant running. The electricity cost was about €0.09 per kW/h (including energy tax and VAT) and the fan used 1.5 kW/h in operation. This meant that the demand-control solution produced an energy saving, per month, of 970 kW/h, and a resulting reduction in running-costs of ca 85.32 €/month. If all residential garages were equipped this way the sum of energy saved would make for a considerable benefit to society and the environment. A larger garage would have saved even more money thanks to the controlled ventilation system.

Ventilation plays a vital role in keeping in door parking spaces safe, especially when busy.

Another benefit is fewer people suffering from CO or CO2 poisoning being admitted to hospitals. As well as being good for the health of the general public, This helps reduce the costs of health care to the government.

Phil Robinson Rotronic UK

Business Case, Calibration, Humidity, News, Sensors, Temperature

Pharmacy Business Case – MEDICINES NEED WATCHING – CLOSELY!

August 11, 2015 rotronicuk 2 Comments

Colleagues from our Swiss based HQ just outside Zurich have shared with us a great example of an increasingly important application based around the monitoring of medicines in typical high street pharmacies. Pharmacies may look like they simply store medicines on normal shelves but most drugs require strictly controlled and monitored conditions to ensure they reach us in perfect condition! Read on to discover more…

Medicines are sensitive products. Moisture or excessively high or low storage temperatures, can impair their quality. Incorrectly stored medicines lose their efficacy, leading to significant health risks. Correct storage is therefore vital, offering as it does the guarantee that medicines remain safe and efficacious and retain their high quality right up to their expiry date.

Meeting GDP/GMP requirements in pharmacies

The storage of medicines is legally regulated by GDP (Good Distribution Practice) Standard 9.2 and is inspected by the responsible authorities on site.

Insulins and other liquid antibiotics for instance must be stored in medicine refrigerators at a temperature between 2 °C and 8 °C. A temperature range of 15 °C to 25 °C applies to the vast majority of other medicines.It is compulsory to document the storage conditions of all medicines.

To help fulfil the legal requirements, Rotronic has launched the new HL-1D data logger – a convenient, precise, reliable logger that is virtually tailor-made for a medicinal environment.

Rosengarten Rotpunkt pharmacy

The HL-1D data logger has undergone exhaustive testing
under real-life conditions in the Rotpunkt Rosengarten
pharmacy. With its simple handling and remarkable price-performance ratio, the logger offers great potential for any pharmacy.

The Rosengarten Rotpunkt pharmacy is deeply rooted in the community of Bassersdorf, Switzerland and has been at its present location since 1985.

In 2011, Mr. Ivan Mihajlovic took over the directorship and today runs the pharmacy with a total of 10 employees.

“The quick evaluation of the data and the understandable visualization of the measurement values in a PDF report meet all QMS requirements and document the data long-term.”

Complete measurement chain

Rotronic offers complete solutions for the entire measurement chain. Even if you are already using other data loggers successfully, we have a range of innovative calibration solutions.

If you require more information or wish to discuss any monitoring, control or calibration applications you may have please do not hesitate to contact us.

Dr. Jeremy Wingate
Rotronic UK

News, Process, Sensors, TechNotes

What is Dew Point Temperature

July 31, 2015 rotronicuk Leave a comment

Our state side colleagues have put together a great FAQ technical note explaining dew point temperature in more detail!

The FAQ technical note can be accessed here and answers the following key questions!

What is dew point temperature?
What is frost point?
When should I choose dew point as the parameter I measure?
What are the pros and cons of measuring dew point versus relative humidity?
Does dew point change as the ambient temperature changes?
How does pressure affect dew point measurement?
What are the common technologies for measuring dew point?
Isn’t dew point temperature the same thing as wet bulb temperature?
How do I know which technology is best for my application?
Where can I buy a dew point instrument?

Rotronic produce precision low dew point sensors for low moisture applications in addition Rotronic UK is the UK distributor for world class MBW chilled mirrors, please contact us for additional information!

Dr Jeremy Wingate
Rotronic UK

Calibration, Humidity, Process, Sensors, Temperature

Temperature, Humidity and Ceramic drying

July 23, 2015 rotronicuk Leave a comment

Introduction

Ceramic drying is one of the most important processes in ceramic production technology. Quality defects of ceramic products are caused by improper drying. The drying affects the quality of the finished product, the throughput but also the overall energy consumption for ceramic manufacturing enterprises. According to various statistics, generally energy consumption during drying processes represents 15% of total industrial fuel consumption. However within the ceramic industry, the energy consumption used for drying accounts for a much higher percentage of the total fuel consumption. Therefore energy saving within the drying process is extremely important for all enterprises. Drying speed, reducing energy use , ensuring high quality products and reducing pollution are all basic requirements for any ceramic manufacturer today.

Measurement and Control in Ceramic Dying

Ceramic production is done through several main processes: casting, drying, glazing, firing…

The casting and drying are important processes for ceramic. A forming workshop is equipped with an intelligent control system. The control system regulates the relative humidity value using information provided via room and process sensors. Sensors have to measure accurately ad repeat ably despite the challenging and often dusty conditions. Humidification and dehumidification processes require substantial energy so tighter control is a huge energy saver for these industries.

A constant temperature is also achieved via the intelligent control system. With a stable temperature and stable relative humidity within the workshop, manufacturers ensure the quality of the ceramic body drying.

After stripping the body from the cast, the body contains a very high relative humidity level. During the drying process, the body may crack or deform due to the speed in which the product is dried (volume and shrinkage) which ruins the product and decreases the throughput.

Exactly this part of the process has become a major bottleneck within the production process of ceramic products.

In a casting workshop, stable environments can reduce the cracking and deformation effectively. It also improves the throughput rate of semi-finished products and shortens the drying period, also prolonging the life frame of the plaster cast.

So constant temperature and relative humidity according to the set values will help all factories to improve the throughput, reach an optimal drying speed and deliver the best quality results available.

How can we help?

Rotronic provides a range of instruments for environmental monitoring and control.

Rotronic HC2-IC industrial temperature and humidity probes, are successfully working in these tough applications, the probes are installed on the roofs of drying chambers and resist chemical pollution. With a flexible HF5 transmitter, the outputs can be set to the customers requirements.

With both digital and a range of analogue outputs available as well as several probe mounting options, products can be selected for all applications.

Measurement data can be viewed on HF5 with display or remotely via HW4 software. Ease of calibration and sensor replacement ensures down time is kept to an absolute minimum.

Dr Jeremy Wingate
Rotronic UK

CO2, Humidity, Temperature

Incubators

May 19, 2015 rotronicuk Leave a comment

Incubators in General

Right from the point when human beings started to cultivate land they were strongly dependent on external influences. The levels of rain, sunshine, CO2 as well as soil quality defined the success rate of plant growth. Like plants, every organism has its specific requirements for optimal reproduction. Incubators are used to artificially generate an organism’s ideal environment. Even the ancient Egyptians learned that the rate of successfully hatched chickens increased drastically when they put the fertilized eggs in a big oven built out of bricks that was permanently heated slightly. Although in that case, only the temperature was “controlled”. The Egyptian egg oven can be considered the earliest incubator. But hatching eggs is only one application where incubators are used. Other important usages are the growth of bacteria, viruses and spores for research, diagnostic analysis or even drug production

“Egyptian Egg-oven.” Published in “The Penny Magazine”, August 10, 1833.

Facts & Figures:

India’s poultry industry has to expand from 2010 until 2013 annually by 12-15% to fulfil local demand only.

The average chicken weight doubled since 1934 and is now around 2.5kg.

The US chicken consumption grew from 22kg per capital in 1980 to 39kg in 2011.

Why the Need to Measure

Various elements need to be measured in order to provide an ideal environment for organisms to reproduce.

Temperature

For incubators that are used for chicken hatching, temperatures from 37.2°C to 37.7°C are ideal for incubators with fan circulation. If the incubator has no fan 38.8°C is recommended for best results. For bacteria generally 35°C is best.

Incubator and shaker for growing cell cultures in liquid media

Humidity

For growing bacteria, high levels of humidity are required, the majority need 90%rh or higher. The widely known food poisoning bacteria “Salmonella“ only grows at 95%rh and above. For most moulds 80%rh is already sufficient to promote growth.

Humidity is also extremely important when hatching chicken eggs. Within the egg is a tiny air bubble that gets bigger during the growth of the embryo, but if the humidity level is to low the fluids that are essential to the final growth of the embryos are lost too quickly. A humidity level between 50-60%rh is considered ideal.

Inside an incubator which is able to control humidity levels.

Carbon dioxide

In nature the CO2 level in a chickens nest is around 0.4% or 4000ppm compared to the surrounding air that has only 400ppm. Keeping the CO2 level in an incubator between 4000ppm to 6000ppm is necessary for a normal development. Especially in the late development of the eggs, the embryonic production of CO2 increases as incubation proceeds and therefore should be removed from the environment to keep the CO2 at a safe level.

Also in the research of cross-breeding or genetically modifying plants, a controlled CO2 environment is key to speed up the development process.

Philip Robinson Rotronic UK

Sensors

Monitoring Transportation

May 12, 2015 rotronicuk 1 Comment

Rotronic has recently released a cold chain logger which can be used to ensure items are kept at the correct temperature during transportation.

Rotronic cold chain logger

Transportation in general

One key aspect of today´s wealth in the modern world is specialization. So towns, regions or even whole countries focus on a few things they are really good at. This can be based on various factors; for example resources offered by the land, climatic conditions or specific knowledge that has been developed over a long period and has been passed on from generation to generation. As an example, Cuba provides brilliant conditions for the Corojo and Cirollo plants, better known as tobacco. Although smoking is quite popular among Cubans, their production of tobacco exceeds the local demand by far. On the other hand they lack other resources and goods. At that point trading, and therefore the importance of transportation, comes into play. In the case of the tobacco the transportation is not a simple task, since it requires a constant high humidity level to maintain the high quality expected from a Cuban cigar.

Tobacco plants in Cuba

Like tobacco there are many products where special requirements for shipping have to be put in to consideration, in order to maintain freshness, internal integrity, colour quality or whatever other properties that could be affected by an inappropriate transportation.

Facts & figures:

A major step in the transportation industry was the international standardisation of shipping containers in 1955. This means that one container can be put directly from a vessel to a truck and transported all around the globe.

Today 28´000´000 ISO containers (20 feet) are permanently on the move, transporting goods from point to point keeping our economy running.

Every year 10´000 shipping containers fall over board.

0.16 Euro cents is the cost of transporting a bottle of Chilean whine to Europe.

Why the need to monitor transportation?

Various factors can have a negative impact on a product during transportation. Below are the most common parameters to be monitored to ensure product quality:

Temperature

Controlling temperature is the key in transporting fresh foods, where the rate of decomposition is reduced significantly by maintaining lower temperatures. It is also important as proof of an uninterrupted cool chain for frozen products or to ensure the effectiveness of medication.

the back of a temperature controlled lorry.

Humidity

Monitoring humidity ensures that the growth of micro organisms in food and medications remains below critical levels. Controlling humidity also helps to maintain structural integrity of paper and cardboard or to avoid corrosion of metals during a long transatlantic journey in a shipping container.

Pressure

Apart of being able to reconstruct when and how long a parcel`s flight was, pressure is also en essential parameter for products that have to be transported in a vacuum or pressured chamber. This method could for example be used when transporting biological samples or hazardous chemicals.

Shock

To guarantee that expensive machinery, glass, works of art and other delicate products weren’t damaged during transportation, monitoring of the G-force in all three axis is the solution.

The Rotronic LOG-HC2 can log light, temperature, humidity, pressure, and shock.

Light

Light is a good parameter to determine if or at what time a container or package was opened. Also to ensure protection of light sensitive products such as vegetable oils, chemical substances or photo paper.

Philip Robinson Rotronic UK

CO2

Measuring CO2 in a Greenhouse

May 5, 2015 rotronicuk Leave a comment

CO2 in Greenhouses in General

CO2 is one of the key ingredients of photosynthesis, meaning it is essential for plants to grow. Monitoring CO2 in a greenhouse allows optimisation of plant growth conditions, resulting in more efficient plant growth and higher crop yield. Different plants need different levels of CO2 in the air to maximise development.

Facts & Figures

One of the largest greenhouses in the world is in Almeria, Spain where greenhouses cover almost 50000 acres (200km2)

In the Netherlands, greenhouses occupy 0.25% of the total land area.

The Netherlands has around 9000 greenhouse enterprises that operate over 10000 hectares of greenhouses and employ some 150000 workers: 80% of the manufactured produce is exported.

Why The Need to Measure CO2

It is essential to monitor CO2 levels at all times because different plants have different needs regarding CO2. Before photosynthesis, CO2 is collected by the enzyme RuBisCO. However, RuBisCO is just as happy to collect O2 as it is CO2. In C3 plants, RuBisCO collects CO2 from the air as soon as it comes through the stomata on the leaf. This means that if levels of CO2 in the air are low compared to levels of O2, the RuBisCO will just collect more O2 and the plant growth will be less efficient. In a C4 plant, there is an extra step during which CO2 is ‘filtered’ from the air and passed on to the RuBisCO. During this extra step, CO2 can be stored, meaning the stomata do not need to be open all of the time, helping to prevent water loss. In the C3 plant, the stomata need to be open more as there is not such storage of CO2. A third kind of plant, a CAM plant, can only collect CO2 at night, as its stomata are closed during the day.

Stomata on a tomato leaf

It is important to have close control of the ventilation of a greenhouse to utilise CO2 to maximum effect without risk
of damaging plants. Generally, the best practice is to provide increased CO2 to young plants and parent plants regularly, and to all other plants for a short period during spring. If the plant is sensitive it is extremely important to have pure CO2, to prevent damage. Up to 1 000 ppm CO2 is estimated as a good level.

If the levels of CO2 are too high in the greenhouse, plants can be damaged. If CO2 levels rise too high, plants will close their stomata to protect themselves, resulting in less transpiration, and therefore less nutrition is drawn through the plant, slowing down growth. CO2 levels vary considerably over a 24 hour period. This is because during the night, plants can stop photosynthesis (in the absence of light) and begin respiring. this means plants will switch from using CO2 to producing CO2.

When there is plenty of light, a plant will photosynthesize, but when light levels are too low plants will begin to respire instead

What is the Result?

If all plants of a crop are grown in the same conditions (including CO2 levels), the chance that all plants will be ready for harvest at the same time is increased. The annual consumption of CO2 in a greenhouse is generally about 5-10 kg/m2, only in exceptional cases does would it be higher. The effect, of using CO2, on profit varies considderably. For example, tomatoes and cucumbers can give 8-10% higher return when growin in optimal CO2 levels. Plants grown in a CO2 enriched environment generally produce greater biomass than other plants, particularly in the roots, allowing faster growth and resulting in stronger plants with an increased reproductive rate.

Philip Robinson Rotronic UK

IAQ Facts:

Why the need to measure, temperature and relative humidity?

Facts and Figures

Why the need to measure CO2?

How does it work?

Reduced Costs

Meeting GDP/GMP requirements in pharmacies

Rosengarten Rotpunkt pharmacy

Complete measurement chain

Introduction

Measurement and Control in Ceramic Dying

How can we help?

Incubators in General

Facts & Figures:

Why the Need to Measure

Temperature

Humidity

Carbon dioxide

Transportation in general

Facts & figures:

Why the need to monitor transportation?

Temperature

Humidity

Pressure

Shock

Light

CO2 in Greenhouses in General

Facts & Figures

Why The Need to Measure CO2

What is the Result?

News, views and interesting things from the world of metrology