Tag Archives: accuracy

A look at the Beer Brewing Process – Just in time for the Rotronic 2014 International Sales Meeting

Beer brewing in general

There is no exact date, as to when the first beer was brewed but already at the beginning of the fifth millennium BC, people in southern Mesopotamia, in a region known as Sumer (modern Iraq), were brewing beer.

Beer, like other commodities such as wheat and other grains, was used as a currency. A clay tablet, dating from 6’000 BC contains one of the oldest known beer recipes.

Beer Map
Beer consumption throughout the world

The basic ingredients of beer are: water; a starch source: which is able to be fermented; yeast: to produce the fermentation; a flavouring such as hops. Yeast is the microorganism that is responsible for fermentation. Specifically Saccharomyces cerevisiae is the species of yeast that is used for brewing.

Facts & figures:
Beer is the third most popular beverage in the world, coming in directly behind tea and water.
American beer is made mostly from rice. This was invented to give American beer a lighter taste and tap into the market of women buyers.
In the UK 28 million pints of beer are consumed every day, which equates to 100 litres per head each year.
Belgium has over 400 different beer brands.
Cenosillicaphobia is the fear of an empty glass.

There are several steps in the brewing process, which include malting, milling, mashing, lautering, boiling, whirl-pooling, fermenting, conditioning, and filtering.

Step by step brewing:
  • Malting: germination of cereal grains. The sprouted cereal is then kiln dried at around 55°C. Milling: grinding of the malted cereal.
  • Mashing: the cereals are mixed with water and then heated.
  • Lautering: separation of the mash: the liquid (wort) is separated
    from the residual grains.
  • Boiling: the wort is boiled to ensure sterility and then hops are added for flavour!
  • Whirl-pooling: the wort is sent into a whirlpool, removing the dense particles using centrifugal force.
  • Fermenting: yeast is added to the wort: conversion of the carbohydrates to alcohols and carbon dioxide – the chemical conversion of sugars into ethanol!
  • Conditioning: the tank is cooled and the yeast and proteins separate from the beer. This conditioning period is also a maturing period.
  • Filtering: the beer is filtered: stabilising the flavour.
  • Packaging: the beer is packed then to the customers
Example brewing process
Example brewing process
Why the need to measure the carbon dioxide?

Carbon dioxide Carbon dioxide (CO2) is a naturally occurring chemical compound. It is a gas at standard temperature and pressure.

We inhale oxygen and exhale carbon dioxide. The carbon dioxide level in exhaled air is rather constant: around 3,8%. When carbon dioxide is exhaled it will quickly be mixed with the surrounding air even indoors and provided that the ventilation is good, the concentration will be reduced to harmless levels. Indoor carbon dioxide levels usually vary between 400 and 1’200 ppm (parts per million). Outdoor carbon dioxide levels are usually 350 – 450 ppm.

Beer brewing process: Heavily industrialised or contaminated areas may periodically have a higher concentration of CO2. Carbon dioxide is released during the beer brewing process and as you will see below, CO2 is toxic for living organisms. In brewery environments where process generated carbon dioxide is widely present, the maximum permitted carbon dioxide concentration according to most standards is as high as 5’000 ppm (5%) during an 8 hour working period.

Beer storage: Most beer leaves the brewery carbonated: beer and carbon dioxide are sealed in a container under pressure. It can be carbonated during fermentation but it can also be carbonated in the bottle. In this case the beer is allowed to ferment completely. It is left unfiltered which leaves active yeast suspended in it. A small amount of sugar is then added at bottling time. The yeast begins to act on the sugar: CO2 is released and absorbed by the beer.

Beer can also be force carbonated, in which case it is allowed to fully ferment. Then CO2 is pumped into a sealed container with the beer and absorbed by the liquid. In this case, a tank of carbon dioxide will also be required. Undetected leaks in a gas system is a costly waste and a safety risk to personnel. While small leaks are inherent in any gas system, those of significant size raise the level of economic and safety risk.

How does CO2 affect the human body?

Due to the health risks associated with carbon dioxide exposure, there are regulations and laws in place to avoid exposure! The US National Institute for Occupational Safety and Health (NIOSH) states that carbon dioxide concentrations exceeding 4% are immediately dangerous to life and health.

In indoor spaces occupied by people: concentrations higher than 1’000 ppm will cause  discomfort in more than 20% of occupants. At 2’000 ppm, the majority of occupants will feel a significant degree of discomfort and many will develop nausea and headaches.

How CO2 affects the body
How CO2 affects the body

Case study: The lake Nyos
The lake Nyos is a crater lake situated in Cameroon. In 1986, a pocket of magma from under the lake, leaked a large amount of CO2 into the air. The result was suffocation of around 1’700 people and 3’500 livestock!

As we take beer brewing seriously we will be sure to test a number of varieties with our colleagues from the world over at the Rotronic 2014 International Sales meeting in Grindelwald next week!

Dr Jeremy Wingate
Rotronic UK

New training course dates! – Temperature and Humidity Measurement and Calibration Training.

Following the continued success of our training courses we have several new dates for October this year!

These courses are aimed at providing excellent theoretical and practical knowledge useful both for those new to the field or those looking to expand their knowledge.

Details and booking information can be found via the below links.

7th – 8th October 2014 :: Two Day Temperature Measurement and Calibration

9th October 2014 :: One Day Humidity Measurement and Calibration

Courses will be hosted by our partner Benrhos Limited in Wales and delivered by Dave Ayres (Benrhos) and Jeremy Wingate (Rotronic).

These excellent value courses are open to a maximum of 8 delegates ensuring course content can be targeted specifically to your needs.

Details and booking information can be found via the below links.

7th – 8th October 2014 :: Two Day Temperature Measurement and Calibration

9th October 2014 :: One Day Humidity Measurement and Calibration

Key areas covered include;
  • Knowledge that is not available from other sources.
  • Terminology and units.
  • Fundamentals of each parameter.
  • Best practice measurement.
  • Calibration methodologies.
  • How to interpret results and spot common errors.
  • Measurement uncertainty.
  • How to use uncertainty budgets and benefit from them.
  • Common instrument types and their advantages/disadvantages.

Any queries please do not hesitate to contact us.

Dr Jeremy Wingate
Rotronic UK

White Paper – Save time and money with modern monitoring and calibration

The text below is taken from a Rotronic White Paper available here in full.

Companies across many industries needing to perform regular monitoring and calibration have never faced a more challenging environment. Stricter compliance requirements mean companies are under greater pressure to deliver accurate and reliable data, whilst internal budget restrictions demand the most cost effective and efficient solutions.

Can modern measurement &  calibration techniques help your business operations?

It is well known that accurate measurements reduce energy use and improve product consistency. Instrument users, calibration laboratories and manufacturers are constantly looking for smarter ways of operating and are responding with innovations that are transforming the measurement and calibration industry.

New ways of working

Industrial environments are now more automated and interconnected than ever before and companies need to ensure that their infrastructure and processes have the ability to respond and adapt to industry changes. With the introduction of newer, more complex instrumentation, organisations can often be slow to recognise the additional business benefits that can be achieved by replacing a traditional method that (offers a short term result) with a more modern method (that delivers a longer term sustainable solution). Implementing a new approach can also help re-position the calibration process from being viewed simply as a cost to business to one that helps deliver improved process and energy efficiencies with a return on investment.

Industry advancements

Historically, in-situ calibration has been the standard approach; however, advances in technology means that there is now a viable alternative whilst still maintaining the growing demand for on-site services. With the market moving away from analogue to digital signal processing, interchangeable digital sensors are proving to be a more practical solution for both large and small organisations alike. As businesses look for greater automation and productivity, modern interchangeable digital sensors are allowing calibration to be achieved much more quickly without the costly implications of operational downtime and on-site maintenance.


Why calibrate? – The only way to confirm performance
In unsettled economic times it can be tempting to simply extend the intervals between calibration cycles or to forgo calibration altogether. However, neglecting system maintenance and calibration will result in reduced performance and a loss of measurement confidence, ultimately leading to a failure to meet compliance standards. Measurement drift over time negatively impacts on processes and quality. Regular, accredited calibration demonstrates compliance, but equally importantly, sends a message to customers that quality is taken seriously and that they can be confident in both the process and the final product.
What is your route to traceability
What is your route to traceability

Traditional In-Situ Sensor Calibration

Until recently most humidity calibrations were performed on-site in-situ. Larger organisations with multiple instruments generally found it more convenient to have their own in-house calibration instruments with dedicated technicians working on-site. Smaller organisations unwilling or unable to invest in on-site calibration equipment had the option to engage the services of a commercial calibration provider.

In most cases, trained instrument technicians are required for in-situ calibration work; the equipment is brought to the probes and generally only one probe can be calibrated at a time. One of the main disadvantages of this process is the impact that it has on production downtime, as typically a salt or chamber based calibration can take more than three hours. Moreover, as the processes or control systems are interrupted during calibration, the actual conditions can be unknown.

Modern Ex-Situ Sensor Calibration

Companies keen to avoid the impacts of in-situ calibration and/or operational downtime caused by the replacement of failed hard wired instruments are opting instead for the flexibility and convenience of interchangeable sensors and modern portable calibration generators. Instead of bringing in equipment to calibrate in-situ, the technician brings pre-calibrated probes directly from the laboratory (on-site or external). Using interchangeable digital sensors, the pre-calibrated probes can be exchanged with the in-situ probes in seconds (known as hot swaps), saving time and avoiding operational disruption. If a wider system loop calibration is required, digital simulators are applied and provide any fixed values exactly and instantly. The old probes are then taken back to a calibration laboratory and calibrated accordingly. This adds the benefit that an external accredited laboratory can be used without issue.

Improved accuracy and traceability?

By ensuring that all calibrations are performed within dedicated laboratories as opposed to ad-hoc locations, better procedures and instrumentation can be utilised. In addition, time pressures are usually reduced as processes and monitoring systems are unaffected during calibration. As such calibrations are typically performed to a higher standard leading to lower associated measurement uncertainty (every calibration will have an uncertainty associated with it – whether it is defined or not). Overall in most circumstances these methods deliver greater reliability, improved traceability and importantly, reduces on-site workload and limits operational downtime.


CASE STUDY – Meeting the demands at the National Physical Laboratory, London.

National Physical Laboratory
National Physical Laboratory, London

When the National Physical Laboratory (NPL) in London needed to replace their entire building management system (BMS), they turned to Rotronic Instruments (UK) for an integrated solution to the sensors and calibration. The NPL was looking for both a complete range of temperature and humidity sensors and instrumentation, and the fulfilment of the calibration and commissioning needs of these instruments. Working closely with the project stakeholders, the Rotronic Instruments (UK) team developed a tailored solution, matching the instruments and service to the project requirements.

The decision by the NPL to replace the BMS was brought about by the need for tighter control, greater reliability and easier calibration. One of the key elements in achieving these objectives was the use of interchangeable probes. This immediately limited time-consuming and disruptive on-site sensor calibration to a minimum. Every probe’s digital output was calibrated in Rotronic Instruments’ (UK) UKAS accredited laboratory, and each transmitter’s analogue output was calibrated using a simulated digital input. To resolve any measurement errors in-situ between the calibrated sensors and uncalibrated BMS, each installed high accuracy instrument was loop calibrated and adjusted. Typical installations errors corrected for to date on the brand new BMS are ±0.5 %rh and ±0.25°C; a significant result for labs requiring tolerances of better than 1 %rh and 0.1°C.

Whilst the use of high performance instruments was essential, not every sensor location or application could justify this approach. However, mindful of the NPL’s long term objectives, even the lowest specification thermistor products were customised to provide long-term performance and low drift. Additionally, a robust commissioning procedure and training for key personnel was developed to enable ongoing commitment to delivering quality measurements. Finally, it was effective communication and regular on-site interaction with all the stakeholders that helped deliver a successful outcome to this substantial project.


Summary

All companies that need to perform regular monitoring and instrument calibration should be constantly reviewing their processes and questioning whether their operations and procedures are delivering the maximum return for their business. As increased regulatory compliance and demands for improved energy efficiencies continue to grow, traditional processes may no longer offer the optimum solution. An organisational mindset change may be needed to move calibration from being seen as a fixed cost to a process that can help deliver business objectives through ongoing cost and energy efficiencies.

With the advent of calibration methods that can significantly reduce in-situ disruption, downtime is minimised, labour costs are reduced and productivity improved. Using interchangeable digital systems increases the accuracy and traceability of calibrations, resulting in higher quality product.

Choosing the right calibration methodology may require new thinking and a different approach, but those companies that get it right will end up with a modern, flexible system that both achieves compliance and delivers long term cost and energy efficiencies to their business.

For more information on the NPL case study or how your business can develop innovative and efficient monitoring solutions please contact us.

Critical monitoring of wind turbines

The future is very encouraging for wind power. The technology is growing exponentially due to the current power crisis and the ongoing discussions about nuclear power plants. Wind turbines are becoming more efficient and are able to produce increased electricity capacity given the same  factors.

Picture2
Worldwide installed wind power per year in MW. (Source GWEC)

Converting wind power into electrical power:

A wind turbine converts the kinetic energy of wind into rotational mechanical energy. This energy is directly converted, by a generator, into electrical energy. Large wind turbines as shown in the picture, typically have a generator installed on top of the tower. Commonly, there is also a gear box to adapt the speed. Various sensors for wind speed, humidity and temperature measurement are placed inside and outside to monitor the climate. A controller unit analyses the data and adjusts the yaw and pitch drives to the correct positions. See the schematic below.

Wind Turbine
Schematic of Wind Turbine Systems

The formula for wind power density:

W   = d x A2 x V3 x C  where :

d: defines the density of the air. Typically it’s 1.225 Kg/m3 This is a value which can vary depending on air pressure, temperature and humidity.

A2: defines the diameter of the turbine blades. This value is quite effective with its squared relationship. The larger a wind turbine is the more energy can be harnessed.

V3: defines the velocity of the wind. The wind speed is the most effective value with its cubed relationship.

In reality, the wind is never the same speed and a wind turbine is only efficient at certain wind speeds. Usually 10 mph (16 km/h) or greater is most effective. At high wind speed the wind turbine can break. The efficiency is therefore held to a constant of around 10 mph.

C: defines the constant which is normally 0.5 for metric
values. This is actually a  combination of two or more constants depending on the specific variables and the  system of units that is used.

 Why measure the local climate?

To forecast the power of the wind over a few hours or days is not an easy task.

Picture3
Off shore wind farms

Wind farms can extend over miles of land or offshore areas where the climate and the wind speed can vary substantially, especially in hilly areas. Positioning towers only slightly to the left or right can make a significant difference because the wind velocity can be increased due to the topography. Therefore, wind mapping has to be performed in order to determine if a location is  correct for the wind farm. Such wind maps are usually done with Doppler radars which are equipped with stationary temperature and humidity sensors. These sensors improve the overall accuracy.

Once wind mapping has been carried out over different seasons, wind turbine positions can be determined. Each turbine will be equipped with sensors for wind direction and speed, temperature and humidity. Using all these parameters, the turbine characteristics plus  the weather forecast, a power  prediction can be made using complex mathematics.

The final power value will be calculated in “watts” which will be supplied into power grids, (see schematic on the right).  Electricity for many houses or factories can be powered by the green energy.

Picture4
Not ideal energy generating conditions!

Why measure inside a wind turbine?

Wind farms are normally installed in areas with harsh environments where strong winds are common. Salty air, high humidity and condensation are daily issues for wind turbines.

Normal ventilation is not sufficient to ensure continuous operation. The inside climate has to be monitored and dehumidified by desiccant to protect the electrical components against short circuits and the  machinery against corrosion. These measurements are required to ensure continuous operation and reduce maintenance costs.

What solutions can Rotronic offer?

Rotronic offers sensors with  exceptional accuracy and a wide range of products for meteorological applications and for monitoring  internal conditions.

Low sensor drift and long-term stability are perfect in   wind energy applications where reduced maintenance reduces operational costs.

The wide range of networking possibilities including RS-485, USB, LAN and  probe extension cables up to 100 m allows measurements in remote or hard to reach places. Validated Rotronic HW4 software makes it easy to analyse the data or it can be exported into MS Excel for  reporting and further processing.

The ability to calibrate  accurately using humidity standards and portable generators on site ensures continued sensor performance!

Comments or queries? Please do get in touch!

 

BlogShot – Rotronic High Precision, Fast Response Sensors for Temperature & Humidity Monitoring in Data Centres

There has been a rapid increase in large stand-alone data centres housing computer systems, hosting cloud computing servers and supporting telecommunications equipment, they are crucial for company IT operations around the world. Data centres must be extremely reliable and secure; many are wholly remote facilities.

Air conditioning is essential to maintain temperature and humidity levels within tight defined tolerances, thus ensuring the longest possible service life of the installed hardware.

Precise temperature and humidity measurement with fast reacting sensors is an absolute requirement. This increases energy efficiency whilst reducing energy costs. Additionally, data centre managers need to be alerted to even a small change in temperature and humidity levels. A separate monitoring system with networked alarms using fast reacting temperature and humidity sensors is installed.

Rotronic ‘standard’ HC2-S interchangeable temperature and humidity sensors are regularly specified for monitoring & controlling conditions in data centres due to their high precision and fast response with long-term stability. Used with a HygroFlex5 measurement transmitter analogue (scalable) or digital outputs are available exactly as required for interface with control systems. The loop can be validated electrically in minutes saving a significant amount of time. Probes can be exchanged rapidly when service work or periodic calibration checks are required.

Contact Rotronic for full product information

Tel: 01293 571000  Email:  instruments@rotronic.co.uk

A relative humidity sensor for any application?

As we continue to measure relative humidity in more and more environments with ever increasing accuracy demands, we are pushing the humble capacitive humidity sensor into new realms.

Accuracy, drift, operating range and chemical resistance are key challenges for the relative humidity sensor industry. Our sensor experts work hard to develop new polymers and construction methods to ensure the best performance. At the same time advanced electronics and probe housings enable digital calibration and complex temperature corrections to further increase accuracy and performance. A final and often neglected part of ensuring a relative humidity probes performance is its filter. The correct filter ensures fast response and environmental protection. Filters also offer mechanical protection and eliminate damage caused by extreme airflow.

However understanding why sensors fail is often difficult to predict or understand. In many cases the chemicals and contaminants that sensors are exposed to are unknown. In these situations often selecting the best sensor can only be achieved through mutual relationships built around quality support and service.

In the UK we have worked closely with many customers and in combination with our Swiss technical divisions to select and develop solutions for some highly aggressive and challenging environments. Some of these projects are examined below in more detail.

Hydrogen peroxide vapour sterilisation.

– Hydrogen peroxide vapour is used to chemically sterilise environments and products by generating a vapour of toxic Hydrogen Peroxide. When the humidity reaches the dew point of the surfaces condensation forms sterilising all surfaces. However the chemicals are also highly aggressive to humidity sensors and constant cycles of saturation worsen the effects.

– Making use of Rotronic’s specifically designed H2O2 resistant sensor as well as additional conformal coating to protect exposed connections in further combination with improved customer understanding around handling and storage, has resulted in a solution that has exceeded customer expectations. Importantly, whilst this was not achieved first time around, through a partnership driven towards the end goal we achieved success.

Chemical damage Chemical degradation on the sensor surface
Commercial composting.

– Accelerated commercial composting is an impressive sight to see. The chemical and biological processes occurring are complex and surprisingly aggressive. The wrong materials can literally become part of the final compost if you are not careful. Chemically resistant sensors help to provide some longevity to instruments but one of the key areas requiring extra attention is around cable and filter design. Modifying a standard industrial grade sensor with bio-resilient cables ensures the probes are not eaten alive!

Highly accelerated life testing.

– As a supplier to many chamber manufacturers and companies providing testing services this is a common application. Chambers are cycled between high and low temperatures and humidities to simulate many years aging over a short period of time. The same effects are happening to the humidity sensor – critical for the control or validation of the chamber conditions. Using industrial sensors with electronics isolated away from chamber space reduces the effects of the sudden changes. But also care taken placing the sensor away from humidity outlets and well into the chamber to avoid stem conduction all help to avoid the sensor becoming saturated as temperature cycle – which is one of the main causes for corrosion and drift. Finally, careful filter maintenance is always important.

Swimming pool monitoring and control.

– Our featured image shows chemical formation on a non-Rotronic sensors connections. Rotronic uses inert metals in the sensor design to reduce the re-activity of the sensor to chemicals in the environments. Swimming pools have a mix of high humidity, chemicals and high temperatures which work together to corrode unprotected electronics. Sensor location is key to avoid direct exposure to spray and neat chemicals. Suitable filters and if required chemical resistant sensors have proven highly successful where other instruments have failed.

So you can see not all applications are easy and we have not even begun to explore the basic issues of accurate measurement and control present with every humidity sensor installation. However our belief and aim is that through communication and partnerships we can provide the right product to ensure the desired mix of performance, resilience and price for our customers – it’s not easy but it makes life interesting!

Dr. Jeremy Wingate

Rotronic UK