A Quick Introduction To…

The British Pendulum Tester (also known as the Portable Skid Resistance Tester) is used to measure the slip and skid potential of pedestrian surfaces and roads. Originally designed to measure floor slipperiness in government buildings, the instrument was later adopted by the Transport Research Laboratory as a means of assessing road safety. The British Pendulum is now the recognised method of assessing slip resistance and is recommended for use by the UK Slip Resistance Group (UKSRG) and the Health & Safety Group (HSE). It is an essential tool for anyone wishing to minimize the risk of accidents on slippery roads and floor surfaces.

It works by means of a swinging arm (pendulum). A specially designed rubber slider – with a defined hardness, resembling that of a barefoot pedestrian, a shoe sole or car tyre (depending on the test application) – is placed at one end. When released from a horizontal position, the pendulum head strikes the sample surface with a constant velocity, creating the same dynamic uplift characteristics of a slipping foot. The distance travelled by the pendulum after striking the surface is determined by the friction resistance. The Pendulum Test Value (PTV) can be read directly from a clearly engraved scale or, using our latest model, the Intelligent Pendulum, from a clear OLED digital display. The PTV is directly proportional to the coefficient of friction (by a factor of 100).

As a scientific instrument, the need for accuracy is paramount. All our instruments are carefully calibrated on-site and, if required, sent to the British Standards Institute (BSI) for certification. This provides users with an absolute assurance of accuracy when testing. Detailed instructions manuals are supplied with each instrument, guiding users through the testing process. In addition, our latest model, the Intelligent Pendulum, displays helpful prompts reminding users of correct practice. Training in the use of the machine is also available.

Munro Instruments takes enormous pride in the superior quality of its instruments. Skilled workmanship and strong, high-grade materials ensure that our instruments always arrive in impeccable condition. Under normal use and service, our products are guaranteed to be free of any defects and are capable of providing many years’ service.

by Edmund Daley

Particle Analysis

The Particle Sense P600 provides continuous, real-time measurements of airborne particulate activity. Using unique light-scattering technology, it monitors particle size distribution (TSP, PM10, PM2.5 and PM1). In workplace mode this can be represented in terms of the three health-relevant particulate mass fractions: inhalable, thoracic and respirable.

Particle size is a crucial when considering air quality in the context of human health. Put simply, the smaller the particle the greater the health risk, as there is a higher chance of it passing from the throat into the lungs and penetrating beyond the terminal bronchioles. Workers in high-risk industries – such as construction or textiles manufacturing (to name just two) – are by no means the only ones affected by particulate matter. Dust, dirt, soot, smoke, soil, acids and metals are capable of travelling large distances, and they choose their victims indiscriminately. Exposure to such particles can cause heart and respiratory problems and even death. Poor air quality presents a very real threat, and it is time we started taking action to protect public health and welfare.

Continuous monitoring is the safest, most effective way of identifying high-risk areas, and it can be used to select the most appropriate relief mechanism. The Particle Sense P600 is a portable instrument equally suited to long- or short-term pollution studies (both indoors and outdoors). It can be mounted inside a special, weather-proof lamp-post box and left unattended in remote locations. Additional sensors can be attached to measure parameters such as wind speed and direction, temperature, humidity and rainfall. The P600 also features two external gas or noise metre inputs.

Real-time data from multiple P600 stations can be monitored using a computer or smart phone. Our dedicated air quality software creates easily analysable graphs and reports, and notifies users of high readings. Alarms are triggered if required.

The Particle Sense P600 works by means of a nephlometer. Airborne particulates are drawn in through a narrow inlet and passed through a laser beam. The individual particles cause the light to scatter, which is then measured by a photometer. This is calibrated such that the amount of light it receives is proportional to the size of the particle. Over 20,000 particles per second can be sized before coincidence effects occur (two particles in the beam at once). Typically, this takes place at concentrations of 6000 micrograms per cubic metre or greater. Using the photometer readings, the microprocessor is able to calculate the expected mass of the particle, as well as the chances of deposition in the respiratory tract (according to conventions outlined in BS EN 481 and EN 12341).

Once particles have passed through the laser beam, they are caught on a filter which can, if required, be used for gravimetric analysis and/or calibration purposes. The instrument is normally fitted with a TSP inlet, but other inlets are also available for size-selective sampling (PM10, PM5 and PM2.5).

by Edmund Daley

Retrofit Your Pendulum

In March of this year, Munro Instruments launched the first ever digitized British Pendulum Tester. The Intelligent Pendulum preserves the trusted mechanical design of the older model, but greatly simplifies and improves the test procedure.

We are now offering existing users of the Munro Stanley Portable Skid Resistance Tester the chance to retrofit their instrument so that it includes the features of the new model.

This would involve integrating a digital read-out onto the scale plate, which clearly displays the Pendulum Test Value and thus eliminates the possibility of parallax error

Added Bluetooth functionality means that the instrument will automatically transmit test results to our specialised slip resistance software. This will generate an instant test report, streamlining the process of data capture and presentation. The software stores an infinite amount of data, and reports can be downloaded at any time.

For more information, please contact info@munroinstruments.com.

by Ashish Acharya

Indoor Air Purification

Air quality can be categorized as Indoor Air Quality (IAQ) or Outdoor Air Quality (OAQ). Whilst there has been considerable publicity and awareness-raising on OAQ concerns, there has been substantially less on IAQ. It is estimated that we spend 90% of our time indoors, and yet we are offered very little in the way of advice to remediate IAQ issues if discovered.

The well-known EU Air Quality Framework Directive (96/62/EC) only considers OAQ; no reference is made to IAQ at all, despite the fact that IAQ is directly influenced by outdoor factors such as road traffic pollution.

Indoor air quality is complex, as it is contingent on both internal and external factors which vary from region to region. As a result, detailed legislation is difficult to implement. A site located next to a busy road will experience different pollutants to a site that allows smoking indoors. Both buildings’ occupants are at risk but in different ways.

A summary of the different types of indoor pollutants is given below [1]:

Pollutant Sources Health Impacts
Carbon Monoxide (CO) Heating and cooking appliances Lethal at high levels; chronic effects at low levels
Nitrogen Oxides (NOx) Heating and cooking appliances, outdoor pollution sources Respiratory symptoms
Environmental Tobacco Smoke (ETS) Cigarettes, cigars, pipes, tobacco Reduced lung function, asthma, lung cancer, heart disease
Radon Ground gases Lung cancer
Particulate Matter (PM) Cooking and aerosols, outdoor pollution sources Reduced lung function, higher risk of lung cancer and heart disease
Allergens Mold, house dust Risk of asthma and adverse health effects
Volatile Organic Compounds (VOC’s) and Ozone Furniture, cleaning products, paint, printers Respiratory tract aggravation, aggravation to lungs

For some time, Munro Instruments has focussed its energies on indoor air quality monitoring. We manufacture and supply gravimetric air samplers and real-time air monitors. In the hope of solving IAQ issues, Munro has teamed up with US company CosaTron Inc. to provide air quality enhancement systems. These are specially designed to improve air filter performance and capture pollutants and pathogens without creating any dangerous by-products in the process.

This patented technology is entirely unique and differs from other filtration technologies currently on the market. Many air filtration systems can in fact worsen indoor air quality. Ultraviolet filters, electrostatic precipitators and plasma technology all create CO2 and Ozone as a result of the filtration process, both of which are known to cause health complications.

Cosatron systems do not create any by-products and have been independently tested, validated and proven to actively reduce particulate concentrations in indoor environments.

The Filtration Process:

The system centres around the natural process of particle coagulation. Studies have shown that 98% of all particulate matter are smaller than 0.5 µm in size. Particles of this size do not follow the laws of fluid dynamics and are not carried with the bulk airflow through HVAC systems. This means that 98% of the particulates in your indoor environment are unaffected by filters.

Particles <0.5µm follow Brownian motion (the random motion of particles) and can only be influenced by complex electrical fields imposed onto the particulate matter. CosaTron technology does exactly that. It utilizes complex electrical fields to excite the particles, causing them to speed up and collide. This results in an exponential increase in the rate of kinematic coagulation. Higher velocities increase the probability of particles colliding and overcoming the activation energy of the coagulation process.

As coagulation causes the particles to increase in size, they can be picked up in bulk air flow of HVAC systems, enabling easy collection and removal. This technology has been independently verified to improve filter efficiency.

The systems can be installed as new or retrofitted into existing HVAC systems of any shape or size. If filters are pre-installed, the technology works to help improve filter efficiency.

These devices do not release any Ozone or CO2 as a by-product and thus represent a step-change in the development of indoor air purification. For more information please contact: info@munroinstruments.com.

by Paul Scott

[1] UK Indoor Air Quality, Post Note No. 366 November 2010.