Tag Archives: control

Energy Efficiency and Reliability in Modern Data Centres

Introduction

Data centres are rapidly becoming the power houses of the modern world. Combined with the rise of digital industries, virtually all business operations now rely in some way on the transfer of data. As data transfer rates increase in tandem with an explosion in mobile communication the demands on data centre infra-structure are ever increasing.

It is estimated that by 2018 global data traffic will exceed 8500 exabytes (32% compound annual growth rate).

Data centres provide the infra-structure to support the transfer and hosting of data. They are often classified into 4 tiers. Tier 4 provides highest levels of redundancy, security and efficiency. For example, a Tier 4 data centre is required to have an uptime of 99.995% equivalent to less than 27 minutes downtime per year! Tier 4 sites have fully redundant systems, power supplies and biometric security. Zero downtime is the ideal as the costs incurred via end user penalties can be huge.

data centre tiers

Why the need to measure temperature, humidity and differential pressure?

Data centres must be maintained to specific environmental conditions to ensure the performance and longevity of the hardware installed. As standard, temperature must be 18-27 °C, dew point 5-15 °C dp and humidity no higher than 60 %rh. This ensures the hardware is at a suitable temperature, condensation is avoided and the chance of static build up is reduced (caused by low humidity).

A control range of ±9 °C may seem relatively broad, however 100% of the energy supplied to server hardware is converted to heat. In most data centres if the cooling system fails and servers are not shut down, heat levels will rise above a critical 35 °C within minutes or even seconds. If unchecked, temperature levels will rise causing hardware damage and can result in electrical fires.

Achieving the specified control range requires precision sensors and advanced control systems. Typically modern data centres are designed using computational fluid dynamics to ensure the very highest efficiency. Despite this it is estimated around 5% of US electrical energy used is for data centre cooling.

pue power usage effectiveness

Since 100% of electricity utilised by servers is converted to heat, theoretically a 100% efficient cooling system would require an equal amount of energy. Efficiency is measured by comparing total facility energy use, with IT equipment energy use. This is called Power Usage Effectiveness (PUE). Theoretically PUE can be 1 but typically reported values are above 2. By utilising precision measurements and design, modern data centres achieve PUEs of ~1.1!

An improvement of 0.5 in a data centre’s PUE  equates to a energy saving of ~£2.2 M & ~12,000 tonnes CO2 over 5 years (for a site with 1 MW load).

 

What solutions can Rotronic offer?

Rotronic provides a range of instruments for environmental monitoring and control. Reliable and precise outside air sensors and weather shields enable natural cooling to be utilised where possible.

Inside the data centres, Rotronic interchangeable HC2-S probes can provide a combination of precise, fast response temperature and humidity measurements with ease of calibration. Our latest PF4 differential pressure transmitters provide precision low drift measurements.

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

Importantly though we aim to understand your needs and build a relationship with the goal of providing an appropriate solution, combining instruments, training, calibration and ongoing support.

Dr Jeremy WIngate
Rotronic UK

 

Timber Drying

We recently visited a company which is involved in the drying of wood, and learned a bit about wood drying. This company had bought a temperature and humidity logger for monitoring their drying environment.

Timber Drying in General

Wood is probably one of the oldest building materials on the planet. But before wood can be used as a construction material, whether it for structural support in a building or to manufacture furniture, it has to undergo treatment to gain the required properties defined by the application in which the wood is used. The first and most important treatment is the drying process.

MINOLTA DIGITAL CAMERAA timber frame for a barn.

The fastest and most effective way to drying timber is in a Kiln. Kiln drying is done in a closed chamber in which air temperature, relative humidity and airflow can be controlled to dry timber to a specified moisture content. The temperature for the drying is usually between 40-90°C depending on type, size and the intended use of the timber. There are many different types of kilns such as vacuum systems, traditional heat and vent type kilns and radio frequency dryers. The cost of installing and maintaining a kiln may often be prohibitive unless a large amount of timber can be processed. However, if the value of specific species is high enough, it becomes more feasible to kiln dry green timber.

Drying_process2Wood in a drying kiln.

Some other drying options timber include: Solar drying where the green timber gets put into a glass house. This option is more often used for drying small amounts of timber. For bigger amounts the Air drying option tends to be used more often. Both drying options are only controllable to a very limited extend since they strongly depend on weather conditions.

Facts & figures:

One cubic metre of freshly felled oak contains approximately 540 litres of water.

Examples for air drying times:

Softwoods: 25mm thick Scots pine that is stacked in April can reach 20 % moisture content by July to August if the summer months are warm and dry.

Hardwoods: 25mm thick English oak if piled in early autumn can reach 20 % moisture content in about 10 months.

A 75mm thick log of wood can even take 3 years to reach equilibrium moisture content.

Why the need to measure humidity?

Controlling humidity during the timber drying process is essential for many factors. An incorrect level of % Equilibrium Relative humidity (ERH) in wood can have the following effects on product and process:

OLYMPUS DIGITAL CAMERAWhen damp, wood is easily damaged.

Dimensional changes

A controlled drying process prevents the timber from unacceptable shrinkage after the installation. But since wood is a natural hygroscopic product it will always change its size to a minor extend.

Strength

Drying the timber below a water contents of 25 % to 30 % will maximise the mechanical strength. dry wood is nearly twice as strong and twice as stiff as green wood.

stess_moisture_plotAs moisture content of wood decreases, the strength increases.

Decay

After drying, timber maintaining less than 20 % moisture content is unlikely to be attacked by wood decaying fungus.

Preservation

To increase the effectiveness of preservative treatments. Many preservatives should only be applied when the humidity of the timber has been reduced.

Corrosion

Drying timber prevents the corrosion of metal fixings such as  nails and screws.

rusty-fixingsWhen wood is wet, it may corrode metal fittings.

Weight

Dry wood is much lighter in weight than wet wood. For many species, dry wood is nearly half the weight of wet wood.

Philip Robinson                                                                                                           Rotronic Uk

Humidity and Seed Storage

I recently visited a facility where they were doing a lot of research into plant biology. As such, it was important for them to have their seeds stored at exactly the correct temperature and humidity to prevent germination or degradation of the seeds.

Seed storage in general

Around 10000 years ago when the first human beings stopped hunting and gathering wild plants, and started to cultivate on farms, preserving and storing seeds became important.

There are various reasons to store seeds, for example, simply preserving grain for consumption later in the year or for sowing during the following season. A little more complex is the collection and preservation of seeds for a longer period of time. This may be done to protect species from extinction or to ensure genetic variety for future generations. Long term storage is also necessary as a back up in case of catastrophic events, such as natural disasters, and disease outbreaks. This type of long term storage is usually done in well protected storage building called seed banks.

Seed-Diversity-in-the-Mil-007A range of seeds in storage

Inside each seed is a living plant embryo which, even in a state of dormancy, breathes through the exchange of gases across its membrane, and is constantly undergoing metabolic processes, also known as aging. The natural lifespan of a seed is influenced by several factors including: permeability of the seed coat, dormancy, and seed physiology. But one of the most important factors is the external environment the seed is exposed to. Temperature and humidity play a key role in the storage capabilities of seeds.

Facts & figures:

The oldest seed that has grown into a viable plant was a Judean date palm seed about 2,000 years old.

The Millennium Seed Bank Project in the UK is the biggest seed bank in the world. Currently they store 31880 species and 1`907`136`030 seeds.

China, with 197 million metric tons, is the world`s biggest producer of rice.

 

Why the need to measure humidity?

Controlling the environment in seed storage is essential for maintaining the germination capacity of seeds, or simply the quality of the seed as a food.

iregi_siteSunflower seeds

In General

Every 1% decrease in the moister content will double the storage life. The same applies for every 5°C decrease of the storage temperature.

A rule of thumb: the sum of the temperature in degrees F and the % relative humidity should be less then 100 for good seed storage conditions.

Storage conditions

Proper storage conditions maintain relative humidity levels
between 20% and 40%, giving corresponding seed moisture contents between 5% – 8%, depending on the type of seed. This range is safe for most seeds. When seed moisture content drops too low (<5%), storage life and seed vigor may decline. When seed moisture content goes above 8%, aging or seed deterioration can increase. Deterioration effects the integrity of the cell membrane, along with several biochemical processes, which overall results in loss of vigor and viability. Seed moisture contents above 12% will promote growth of fungi and insects. Most seeds cannot germinate until seed moisture contents go above 25%.

seedgrowthA newly germinated seed

Seed preparation for long term storage (Seed bank)

To prepare for long term storage, seeds are first put in to a drying room where temperature and humidity is carefully kept at 15°C and 15% relative humidity. Under these conditions the seeds gradually dry out. They are then cleaned, counted and put into airtight containers, before being placed in a seed bank at -20°C. The seeds are then tested for viability on a regular basis.

Philip Robinson                                                                                                                        Rotronic UK

Humidity in Archive Stores

We recently visited a record office to help set up a wireless temperature and humidity logging system in their archives. They had been experiencing problems with mould growth on the records, some of which could be over a thousand years old. To reduce the levels of damage to the records, they wanted to be able to closely control temperature and humidity levels.

Archives in general

Archives are an accumulation of historical documents collected over the life-time of an organisation.

National archives collect, catalog, and secure historical & present day materials from their country. Besides preserving & organising collections, archivists face the great challenge of deciding which records are assigned a lasting value for research purposes and could contribute to the understanding of the country’s history.

Furthermore, archivists transfer the information to more resistant media by digitising documents, drawings, and photographs. This makes it easy for researchers to access conserved items without the risk of damaging the originals.

OrphicPrayerSheet, 3rd Century BCE

Ancient  Etruscan script

In spite of all the new media available these days some legacy materials need to be preserved in order to show their uniqueness. The oldest preserved book in the world is possibly an Etruscan script discovered in Bulgaria. It is estimated to be more than 2,600 years old.

Besides all the academic work necessary it requires great technical effort to create the best possible storage conditions suitable for the form of the objects to be preserved. For example; papyrus and paper require different temperature and humidity conditions compared with microfilm tapes.

Environmental factors in archive stores

– Radiation in the form of light will cause paper to yellow and ink to fade considerably.

– Air pollutants such as dust and chemicals accelerate the degradation of important documents.

– Vibration for example of archive stores caused by vehicular traffic or construction work can cause mechanical stress on collections.

– Insect pests can lead to severe damage through bites and deposits.

– Temperature & humidity are the most significant factors that have an impact on archive collections and often interrelate with other environmental factors.

Why the need to measure relative humidity?

As in museums, incorrect temperature and humidity levels cause damage to documents, books, photographs and drawings. The rate of decay can double with an increase of as little as 5 °C. Generally warm & damp conditions provide more energy and so increase the speed of decay.

High temperatures can cause document wax seals to soften and even result in the combustion of cellulose nitrate film. At low temperatures organic and plastic materials become brittle making them prone to physical damage. However, one of the most significant consequences of incorrect temperature is the incorrect relative humidity that can result – temperature has a direct effect on relative humidity and vice versa.

This particular fact of course is the same in museums, but is often much harder to control in archives since proper ventilation is not easy to achieve in between multiple shelves fully loaded with collections. Studies have shown large deviations of temperature and therefore also humidity (RH) within an archive section. In general, it is recommended to keep the temperature between 20 – 22 °C and humidity be-tween 50 – 60 %rh in archives where organic material is stored. Otherwise a temperature drop can make condensation inevitable.

book1

A damaged book.

RH above 65 % encourages mould and pest activity, RH below 45 % leads to desiccation, shrinking and cracking of organic materials.

The main challenge for architects, and heating, ventilation and air conditioning engineers is to create the most homogeneous controlled storage environment possible.

Philip Robinson                                                                                                       Rotronic UK

Sugar Production and Relative Humidity

The sugar market worldwide

Sugar is one of the most important raw materials traded on the worldwide markets.

Top 5 sugar producing companies

1. Suedzucker AG,

2. Cosan SA Industria & Comercio

3. British Sugar PLC

4. Tereos Internacional SA

5. Mitr Phol Sugar Corp.

In the 18th century only a few countries were producing sugar. However, these days over 100 nations process different base materials into sucrose. Remarkably India, China, Brazil & the European Union alone deliver 50% of the global demand.

Sugar Facts:

– Worldwide 170 million tons of raw sugar were produced in 2011/2012

– Brazil, India, China & EU are the most important sugar producing nations

– With an annual consumption of more than 24 million tons India, is the world’s largest market for raw sugar

Raw materials & processing

In temperate regions such as West, Central & Eastern Europe, the United States, China and Japan raw sugar is produced from sugar beet. However in the tropics and subtropics sugar is extracted from sugar cane.

800px-cut_sugarcane

Sugar cane & Sugar Beet

Processing

The processing of these two raw materials only differs in the first few steps. The main goal is to extract the juice, containing the sugar,  as efficiently as possible.

Extracting the sugar

Sugar cane is cut into small pieces during the harvest. It is then put through an industrial press to squeeze out the sweet sap.
Sugar beet has to be processed in extraction towers, where the plants release their sugar during a hot water treatment at 70°C.

Evaporation

After filtering the juice the water is extracted by passing through different stages of evaporators until only a thick syrup is left consisting of around 70% sugar.

Crystallisation

The syrup is then boiled until sugar crystals are formed. These crystals are then cleaned through centrifugation. To further improve purity this process is repeated twice.

Cooling & drying

Now the sugar has to be dried. One option is in large scale drum dryers at a temperature of 60°C. after drying, the sugar is cooled down on fluidized-bed coolers before heading to the warehouse or packed for shipping.

Trommel2_400_219_01

Inside a drum dryer.

Storage & logistics

Sugar belongs to the group of hygroscopic goods with an extremely low water content – below 1.5%. Basically sugar is a robust material but vulnerable to high humidity and temperature changes.
Generally it is recommended to store and transport sugar at a temperature of 20-25°C and 25-60% relative humidity.

By taking a closer look at the adsorption curve of sugar it is easy to see that over a long range of relative humidity the product quality is not affected. But as soon as the humidity level rises to 75% sugar starts to clump and above 80% relative humidity even dissolves .

Storage

Immediately after production the refined sugar is stored in humidity controlled sugar terminals or ventilated silos connected to dehumidifiers.

6.2.4. Sugar Terminal 5086

Sugar in a storage terminal

Logistics

Large quantities are trans-ported in silo trucks or train wagons. When sent by ship sugar is packed in double-walled bags made of natural fibre and plastic. If sealed like this, temperature is the crucial parameter which can affect the quality of the sugar. Due to big differences in temperature water vapour left inside the bags may cause clumping and even liquefaction.
The finer the sugar, the higher the risk of clumping.

Caking-dark-brown-sugar

Sugar clumping

Why the need to measure humidity?

As seen above, temperature and humidity measurements are crucial parameters in the sugar industry. Due to its hygroscopic behavior sugar can resist small changes in humidity, and slight temperature variations are not a major problem. But as soon as relative humidity rises above 80% or temperature changes significantly, the product can be destroyed as it clumps or even turns liquid.
During the process of evaporation, crystallisation, drying and cooling temperature and humidity play a huge role.

Philip Robinson                                                                                                        Rotronic UK

 

Humidity Control & Pharmaceutical Tablet Coating

Tablet coating in general

Pharmaceutical tablet coating involves the application of a coating composition to a moving bed of tablets with the use of heated air to facilitate the evaporation of the solvent. Several different types of coating are typically used.

Tablet Coating
Tablet Coating Machine
  • Sugar-coated tablets are coated with a coloured or an uncoloured sugar layer. The coating is water soluble and quickly dissolves after swallowing. The sugar-coating protects the encapsulated drug from the environment and provides a barrier to objectionable tablet taste or odour.
  • Film-coated tablets are compressed tablets coated with a thin layer of a polymer that forms a skin-like film. This is usually coloured and has the advantage over sugar coatings  that it is more durable, less bulky, and works faster at the desired location in the gastrointestinal tract.
  • Enteric-coated tablets have delayed release properties. They are designed to pass unchanged through the stomach to the intestines, where the tablets disintegrate and allow the drug to dissolve and start its effect. Enteric coatings are used when the drug substance itself would be destroyed by gastric acid or is irritating to the gastric mucosa.

Facts & figures:

Aspirin is one of the most used drugs in the world – approximately 35,000 metric tonnes are produced annually, enough to make over 100 billion aspirin tablets.

Americans consume 80% of the world`s supply of painkillers — more than 110 tons of pure, addictive opiates every year.

How can accurate measurements help?

Environmental control is the practice of managing the temperature, humidity, air circulation, ventilation and air pressure of a given space. Within certain types of pharmaceutical manufacturing processes, precise environmental control can help limit inefficiencies and potential problems.

Pharmaceutical tablet coating is one such application. Inefficiencies during the coating process may result in contamination and tablet impurity in the form of tablet-to-tablet colour variation, surface pitting from over-wetting, twinning due to spray drying, cracking or peeling. Most of these problems can be overcome by better control of the environment within the process. Over-wetting, for example, occurs when the coating hits the still wet tablet surface and the surrounding air does not dry it quickly enough. Another example involves spray drying, when the coating hits the tablet surface after the moisture has been removed resulting in poor adhesion of the coating.

In the case of incorrect cooling and drying of the sugar solution, a rough, translucent and uneven coating may be produced.

Since the required environment for a perfect coating strongly depends on the composition of the tablets, many pharmaceutical manufacturers have scientists who perform experiments to determine the ideal coating procedure including temperature and humidity levels. Once these specific requirements are determined, the set-points can be configured at the controller to enable the precision tablet-coating machines to work at optimal performance.

spoonfull of medicines
A spoonful of perfectly coated tablets!

Tablet Coating Benefits-Summary

  • covers the unpleasant taste, odour and colour
  • provides physical and chemical protection for the medicine (light, moisture and air)
  • controls the release of a drug (enteric coating)
  • improves the appearance of tablets
  • easier to swallow the tablets
  • assists and facilitate the identification of a drug
Dr. Jeremy Wingate
Rotronic UK

Moisture and Microscopy – Guest Blog from Surface Measurement Systems Ltd

Jan Gorgol, Product Manager at Surface Measurement Systems Ltd based in London has put together an interesting blog on the impact of moisture on modern microscopy. We hope you like it! 

Moisture affects a huge range of materials in very broad industries and research areas.

One of many tools used in characterising moisture effects is Microscopy , ranging from light microscopy including dark-field, light field or cross-polarisation to Raman or FTIR microscopy’s and more esoteric imaging techniques such as Atomic Force Microscopy , 3D X-Ray Tomography or PAM.

Some of the diverse areas where different kinds of microscopy can be effectively used to study the effects of moisture and humidity on real life situations include:

Pharmaceutical

  • Studies of crystallisation of amorphous samples under humidification including hydration of stable and unstable hydrates, deliquescence and liquefaction of hygroscopic samples, co-crystallisation and solvate desorption at high humilities.
  • Polarized light microscopy and birefringence can be used effectively to study Crystal morphological growth. Polymorphism can be studied by Raman, FTIR, and light microscopy. [1]
Light microscopy of PVP drug carrier showing welling and Coalescence at humidity
Light microscopy of PVP drug carrier showing welling and Coalescence at humidity

Cosmetics

  • Hair colour, pigmentation, thickness, tensile strength, shape, decomposition and effects of hair products have been studied with Light and Raman Microscopies.

Paper and environment

  • Polarised light microscopy can be used to study Sludge and dry solids from paper mill residues for evaluation of recovery of wood fibres, pigments, and other paper additives.
  • Polarised light microscopy is also effective in Biodegradable fibres decomposition studies.

Wood

  • Characterisation of wood and vegetable fibre pigments using FTIR and Light microscopy
  • Studies of wood swelling in 3D using X-ray tomography.
  • Studies of effects of humidity on wood adhesive coatings using AFM

Food

  • Effects of humidity on flowability of lactose due to changing amorphous and crystalline content using Raman and light microscopy.
Light microscopy of Amorphous Lactose Crystallisation with humidification
Light microscopy of Amorphous Lactose Crystallisation with humidification
  1. a) Surface adsorption 0% RH
    b) Bulk absorption &surface adsorption 50%RH
    c) Recrystallisation 60%RH
    d) Crystalline Material 90%RH
  • Moisture Induced Phase Transitions of food flavouring studied by light microscopy.
  • Moisture content of seeds has been studied using photo acoustic microscopy helping sustainable agriculture development.
Sucrose crystals at 200X at 95%RH
Sucrose crystals at 200X at 95%RH
  • Effects of humidity on dry milk powders measured using light microscopy [2]
Photographs of Milk powder at 64%, 81% and 85% RH
Photographs of Milk powder at 64%, 81% and 85% RH

Optical coatings

  • Use of phase interference contrast microscopy to study Degradation of anti-reflective optical coatings due to delimitation

Fibres

  • Study of humidity related swelling of wool & cotton fibres using scanning probe microscopy
Tissue paper showing fibre orientation and weave pattern at 95%%RH 200X
Tissue paper showing fibre orientation and weave pattern at 95%%RH 200X

Biological

  • Effects of Humidity and CO2 in live cell imaging incubators

Bacteria

  • Effects of humidity on morphology and elastic properties of Bacteria using AFM

Minerals and Rock

  • Raman Microscopy has been used to study phase changes in Portland cement

Building Materials

  • Critical humidity control in microscopy of microcracked slag materials
  • Slab curing studies related to moisture sensitive floor covering such as wood, PVC, rubber backed carpets,lino and related effects such as delamination, peeling, blistering, staining, etc

These are just a few areas where microscopy can be valuably used to study the effects of changing humidity on real life sample. To help meet Scientists and Technician’s many needs in these areas Surface Measurement Systems have developed an environmental microscopy cell GenRH-Mcell [3] to enable precise critical humidity Microscopy studies in situ.The RH probe chosen for this cell was supplied by Rotronic based on its accuracy, small footprint and excellent quality.

Please feel welcome to contact me jgorgol@surfacemeasurementsystems.com if you have any humidity generation needs in such areas or are interested in adding critical humidity control to other analytical techniques such as DMA,TGA,DSC,XRD, contact angle or process control areas, sample conditioning, mechanical or tensile testing, rheology, powder flow, and so on. Overview of such applications at http://surfacemeasurementsystems.com/products/genrh-family/product-presentation/

References
[1] Dependence of cocrystal formation and thermodynamic stability on moisture sorption by amorphous polymer. David Good,   Crystal Miranda and   Naír Rodríguez-Hornedo
CrystEngComm, 2011,13, 1181-1189
[2] SurfaceMeasurementSystems Application Note 503 – Investigating Dried Milk Powders Using Optical Microscopy at Different Humidity Conditions.
[3] SurfaceMeasurementSystems Application Note 501 – Environmental Microscopy using the GenRH-A Humidity Generator and Mcell Accessory.

About the author:
Jan Gorgol studied Physics at Bristol University followed by a Masters at Brunel University while running XPS & SEM at the Experimental Techniques Centre. After working extensively in Surface science instrumentation globally he now is Product Manager for the GenRH series of humidity generation products at Surface Measurement Systems Ltd.

Related Article blogs:
1. Formulation, Microscopy and Moisture

2.http://surfacemeasurementsystems.com/applications/microscopy-and-moisture/

Interested in sharing a blog? Please contact us!

Dr Jeremy Wingate
Rotronic Instruments (UK) Ltd
jeremyw@rotronic.co.uk

Humidity measurement in Paint Spray Booths

Paint booths in general

Spray painting has existed since the late 1800’s. The technique was developed in a bid to accelerate painting times compared to brush painting. Spray painting is a method of painting where paint is atomised onto a surface via a spray gun. The paint is mixed together with a solvent or water (called a carrier) so that it can be applied correctly.

Cars, aircraft, boats and other such equipment is often spray painted in a spray paint booth.

A spray booth is an enclosed room, designed for spray painting. Depending on the requirements, the booth may be equipped with filtered air to avoid getting dust in the room and an exhaust air system to clear the fumes of any evaporating solvents used during the spray painting process.

Regulations, such as the Occupational Safety & Health Administration from the United States department of Labor have a criteria for design and construction of spray booths state that a spray booth is: a power-ventilated structure provided to enclose or accommodate a spraying operation to confine and limit the escape of spray, vapour and residue, and to safely conduct or direct them to an exhaust system.

Spray paint booths regulate relative humidity, temperature, airflow and pressure to ensure a quality coating and a perfect curing.

Certain paints contain flammable solvents which release flammable fumes: in this case explosion-proof components are required for all measuring equipment that come in contact with the fumes.

Paint dry and cure times
Paint dry and cure times

Why do we need to monitor and measure in Paint Spray Booths

In order for paint to dry correctly within the paint booths, the relative humidity and temperature levels should be within the following conditions:

 – 65 to 75%rh
 – 20 to 24°C

Based upon the intake air, there may be a requirement to either dry or humidify the air in order to reach the desired values. From the temperature side, exactly the same thing: the air might need to be cooled or heated depending on the outside temperature.

Additionally, paint booths might have a  separate monitoring system inside the booths in which the different elements are painted. In order to ensure that the paint is  applied correctly to the element to be painted, it is important to ensure that the surface temperature of the element is not too close to the dew point level in the booth.

If the surface temperature of the element to be painted is close to the dew point temperature, then there will be risks of condensation forming on the surface of the element. If this were to happen, the coating will not be optimal and the drying and curing phase will not be completed properly and the results could be catastrophic.

 

Rotronic have recently launched a totally new range ATEX (Intrinsically Safe and Explosion Proof) instruments. Paint spray booths typically require ATEX certified instruments.

More details here.

Rotronic ATEX range
Rotronic ATEX range

 

Greenhouses and environmental control

The idea of growing plants in environmentally controlled areas has existed since Roman times. The emperor Tiberius ate a cucumber-like vegetable daily. The Roman gardeners used artificial methods (similar to the greenhouse system) of growing to have the vegetable available on his table every day of the year.

The next step from the conventional greenhouse as we know it today will be the introduction of “vertical farms”. Currently, sophisticated so called “plantscrapers“ are being planned or are already under construction in Sweden, Japan, China, Singapore and the United States.

Skyscraper

Skyscraper farming might yet be a possible answer to the question of how to feed the nine billion people that are expected by the middle of the century. These types of green-houses have a tightly con-trolled level of temperature, humidity & CO2, sophisticated watering systems and in addition to sunlight, advanced artificial LED lighting that is specifically designed and installed for each plant family. This way, the crops grow much faster and very efficiently all year round. It is estimated, that the Swedish plantscraper that is planned to be 54m high, will produce thousands of tonnes of food a year, enough to feed up to 30,000 people.

Facts & figures:

  • Tomato is the second most important commercial vegetable crop after potato. Current world production is about 100 million tonnes produced on 3.7 million hectares.
  • In the year 2000, per capita consumption of fresh tomatoes in the U.S. was 17.8 lb,/ 8.73 kg.
  • About 85 percent of the world’s soybeans are processed, or “crushed,” annually into soybean meal and oil. Around 98 percent of the soybean meal that is crushed is further processed into animal feed.
  • The Food and Agriculture Organization of the United Nations (FAO) reports that world production of carrots and turnips (these plants are combined by the FAO for reporting purposes) for calendar year 2011 was almost 35,658 million tonnes.

Why do we need to measure humidity?

Greenhouse humidity levels are important both in prevent-ing plant diseases and promot-ing healthy and strong plant growth. High humidity can promote Botrytis and other fungal diseases. High humidity also restricts plant transpira-tion, which in turn limits evapo-rative leaf cooling and can lead to overheating of plant foliage. If high humidity persists for a long time, the restriction of transpiration can limit the “transpiration stream” of nutrients and can lead to nutrient deficiencies.

Low humidity levels are best avoided because these may increase foliar transpiration to the extent that the root system cannot keep up. Humidity is perhaps the most difficult of the greenhouse conditions to control. Most growers simply aim to avoid the extremes of humidity. Over most temperature ranges, a greenhouse humidity of 50 – 85 %rh is generally safe. Low humidity can be managed with the use of misters and foggers. It is also useful to shade plants under conditions of low humidity to reduce the rate of transpiration.

Transpiring plants add water vapour to the greenhouse air, increasing the humidity inside the greenhouse. Therefore, managing high humidity starts with ventilation control. Replacing warmer, humid greenhouse air with cooler, drier external air. Ventilation also involves significant energy losses, and therefore ventilation must often be accompanied by heating. Therefore, lowering greenhouse humidity with a combination of ventilation and heating increases energy costs significantly.

Candice 
Area Sales Manager