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Ramp Test vs Pendulum

Wet floor

It is not uncommon to find slip ratings on flooring products such as tiles and laminate. These are usually represented as R-values or Pendulum Test Values (PTV).

Whilst many flooring professionals rely on R-values or PTV as a measure of slip resistance, these are commonly misunderstood. Following guidance by the Health & Safety Executive (HSE) and UK Slip Resistance Group (UKSRG), use of the Pendulum Tester is becoming more prevalent due to its portability, cost-effectiveness and suitability on a wider range of flooring surfaces.

In this post we take a closer look at the Ramp test and Pendulum testing procedures, and their respective applications, benefits and disadvantages.

What is a Ramp Test?

The Ramp Test involves an active participant standing on a ramp protected by a fall restraint harness. The operator, wearing standard footwear or barefoot (depending on the standard), walks backwards and forwards over a sample of a flooring material that has been evenly coated with a contaminant - either oil or soapy water depending on the standard. The test starts with the ramp in a horizontal position; the operator gradually increases the angle of inclination until the limit of safe walking is reached and the test person “slips”. The acceptance angle obtained is used to express the degree of slip resistance (the “R” value). The German ramp test method is recognised worldwide (Europe, Australia, New Zealand, Singapore and the Ceramic Tile Institute of America (CTIOA)).

3 types of Test methods:

DIN 51130: A German standard that uses a cleated work boot and oil. A common problem is interpreting the data produced. It is presented as a scale running from R9 (the most slippery) to R13 (the least slippery). It is a common misconception that the scale starts at R1 and that R9 is therefore a safe rating.

DIN 51097: A German standard that tests slip resistance of flooring in barefoot conditions using soapy water as a contaminant. Results are presented in a scale running from A (most slippery) to C (least slippery).

HSL ramp test: The HSL ramp test forms the basis for the British Standard (BS 4592) and uses footwear soled with slider 96 rubber and clean water as a contaminant. Results are presented as CoF (co-efficient of friction). A version of this test can be used to test footwear.

What is Pendulum Testing?

Also known as the British Pendulum Tester, the Portable Skid Resistance Tester was originally designed in the 1940s to measure the slip resistance of floors in government buildings. During the late 1950s, the instrument was adopted and redesigned to study problems in the design and maintenance of public highways, and to test the frictional resistance of new roads, road markings and iron works.

Today, the Portable Skid Resistance Tester is most commonly used to test the slip resistance of roads, pedestrian walkways, office surfaces, shopping malls floors, factories, airports and sports facilities – both at the design stage, after installation and in the investigation of accidents.

Test Methods:

Tests can be carried out in accordance with a variety of different standards. These include BS EN 13036-4, BS 7976-2, BS EN 1097-8, BS 812-114, ASTM E303, AS 4586 and AS 4663. These are broadly similar, but there are some minor variations. Unlike the Ramp Test, tests can be carried out In-situ.

Benefits of R Numbers:

  • The ramp test can produce very consistent results. The person walking on the ramp is trained to walk a specified pace to reduce variations.
  • Ramp testing can be used to test mats and surface coverings that may be unsuitable for the Pendulum.
  • The ramp test can test floors and footwear and provides results in terms of coefficient of friction (CoF).
  • The ramp test can assess a specific sole, heel material or tread pattern and can be used on a variety of flooring types.

Disadvantages of R values and Ramp Testing:

  • Ramp testing uses oil or soap as the contaminant, whereas water is more commonly implicated in slip accidents
  • Ramp tests are unsuitable for assessing the effectiveness of cleaning regimes or changes in the performance of the floor that may take place over time
  • The Ramp Test is laboratory based and cannot be carried out in-situ on flooring that has already been installed.
  • Interpretation of the R values isn’t straightforward. Each ‘R’ value contains a range of possible results making it difficult to ascertain how slippery a floor is.
  • Tests are expensive and usually must be carried out by a third party
  • German Ramp Test standard uses a cleated work boot and oil as the contaminant. If this is not representative of the area where the floor will be installed, the results may be misleading.

Benefits of Pendulum Skid Resistance tester and PTV:

  • The preferred test method of the Health & Safety Executive (HSE), the UK Slip Resistance Group (UKSRG) and the Tile Association in the UK.
  • Used extensively for large-scale commercial projects
  • Can provide results in both wet and dry conditions
  • Can be operated by one person
  • Can be used in situ to assess the slip risk of floors that have been already installed
  • Can be used to test small samples.
  • Can be used to assess the effects of cleaning regimes and repeated footfall on surfaces.
  • Contaminant doesn’t only have to be water – Can be any potential real-life contaminants
  • Instruments can be used by businesses internally without the need for expensive third-party testing.
  • Straightforward to use.
  • International recognised.
  • Can simulate a shoe sole or bare foot.

Disadvantages of PTV and Pendulum Skid Testing:

  • Although the equipment is portable, it is on the heavy side (12.5 kg).
  • Testing process can be time consuming
  • Test standards are not streamlined worldwide
  • Not widely recognised in United States of America

Which is more cost effective?

The Ramp Test is a large fixed piece of equipment designed for use in a laboratory only. It can be used to assess how different types of flooring surfaces perform with different types of footwear. However, owing to its size, testing can only be performed before a floor is laid,

The Pendulum Tester is portable, meaning tests can be carried out on site without having to remove a sample.  This also provides a more accurate picture of the real-life slip risk. The Pendulum can also be used by tile and flooring companies to carry out internal product testing quickly and easily. This can assist with R&D and offering better customer recommendations.

Overall, the Pendulum tends to be much more cost effective option. Due to the size of the Ramp Test, the need for trained operators and strict laboratory conditions, ramp testing is significantly more expensive. Pendulum tests also tend to be the quicker option, meaning they are ideal in situations where results are needed promptly.

The Health and Safety Executive (HSE), UK Slip Resistance Group (UKSRG) and Tile Association (TTA) recommend the Pendulum test method for assessing slip resistance.

Ramp Test vs Pendulum

For further information about the Pendulum Skid Resistance Tester, get in touch via email ( or by telephone (+44 (0) 20 8551 7000).

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Farming and Pollution


The rise of large-scale factory farms in recent years has raised questions about their impact on surrounding areas. What pollutants are they putting into the air?

Researchers from the Earth Institute at Columbia University found that where farm emissions combine with industrial waste and vehicle pollution this leads to the creation of harmful aerosols.

Particulate Matter

The study discovered that industrial emissions release large quantities of nitrogen oxides and sulphates. These compounds combine with chemicals, mainly ammonia gas from livestock waste and fertiliser, to create dangerous fine particulate matter known as PM2.5. Inhaling PM2.5 can lead to respiratory problems, bronchitis, a decline in lung function and organic dust toxic syndrome. In some cases smaller particulates can be absorbed into the blood stream and go on to affect the major organs.

In one experiment, researchers from Texas Tech placed air samplers 10 to 30 metres upwind and downwind from animal farms between the months of October and March. 60% of the downwind samples and 30% on the upwind samples contained tetracycline antibiotics from airborne manure particles.

In recent years the factory farming industry has proposed “good neighbour” policies to reduce the sights, sounds and smells of modern factory farming and to prevent/reduce water pollution. This has been difficult to sustain due to the rising costs of complying with environmental regulation and animal welfare concerns. More farm waste is inevitable.

However, factory farm emissions must combine with industrial pollutants to make hazardous aerosols and particulate matter. Some organisations have argued that the tighter regulations on industrial pollutants are enforced, the more popular clean sources of energy will become. And if fossil fuel emissions are drastically reduced, farm emissions will be starved of the necessary compounds to become dangerous aerosols. If future industrial emissions go down, farm-produced ammonia will float high up in to earth’s troposphere. There, lightning and other natural processes could potentially create fine particulates, but most of these particles would be trapped by raindrops and removed harmlessly.

All this said, vast quantities of animal waste and excess fertilisers wash off industrial fields each year into the surrounding environment, polluting land and water and disrupting ecosystems. And sulphates, a by-product of industrial processes, have been credited with reflecting solar radiation thereby reducing ongoing global warming caused by other fossil-fuel emissions. But, as stated by Susanne Bauer, an atmospheric scientist at Columbia: “It’s all pollution, but in some sense, some of it is good. We must decide: do we want a small cooling effect, or do we want clean air?”.

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Climate Variability

Countries across the globe have experienced severe weather changes throughout the past few months.

The UK was affected by an extreme heatwave last week, with temperatures rising to a scorching 34 degrees Celsius. This prompted the government to issue a level three amber heat alert and place emergency services on standby.

Meanwhile, 4,255 miles away in the southern states of the USA there were reports of a tropical storm affecting millions of people. To date, this has caused two deaths as a result of the heavy rain and harsh winds.

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A Brief History of Munro

Remove this cover for maintenance

Munro Instruments was founded in 1864 by Robert William Munro (1839-1912). The company quickly established itself as a world-leading developer and manufacturer of meteorological equipment.

R.W. Munro became particularly well known for his work on anemometers. After the Tay Bridge disaster in 1879, when a rail bridge collapsed during a violent storm, government authorities realised it was important to create an instrument that could reliably indicate wind force. R. W. Munro was commissioned to assist William Henry Dines, a meteorologist, in building the Dines Pressure Tube Anemometer.

Other equipment at that time included mechanical tide gauges, water level recorders and an early seismograph developed in conjunction with Professor John Milne. In 1907, using one of these devices Milne was able to pinpoint the source of a small tremor in London to the west coast of South America.

Outside of meteorology, R.W. Munro developed a range of innovative products for other industries. In 1880, the company was awarded a contract with the Bank of England to construct a machine capable of printing and numbering bank notes. Fourteen machines were made in total that produced deckle-edged banknotes varying from £5 to £1000. They were printed in batches of eight and the machine was capable of printing 3000 notes an hour.

Nowadays, Munro Instruments manufactures a range of environmental monitoring equipment and health-and-safety apparatus. Staying true to our origins, we continue to manufacture a range of anemometers, alongside air samplers pumps (to measure particulate mass concentration) and the British Pendulum Tester (to assess the slip/skid resistance of pedestrian surfaces and roads). We are proud to be continuing the important work of Mr Munro!

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IM159 Anemometer

The IM159 is a precision-built handheld anemometer made from non-ferrous metal. Wind speed readings are shown on an analogue scale calibrated in knots, metres per second or miles per hour. We use a wind tunnel to calibrate the device and can issue a certificate of conformity.

The IM159 Handheld Anemometer is a mechanical instrument and requires no battery or form of electricity. It is manufactured to British Meteorological Office specifications (ref. 23510) and is ideally suited for use as a contingency device in case automated sensors become unavailable. Its primary application is on offshore helidecks (see CAP 437: Standards for Offshore Helicopter Landing Areas).

It is advised that the IM159 is serviced annually to ensure it continues to function optimally and provide accurate readings.

If you would like to receive further information about the IM159 Handheld Anemometer, please get in touch via email ( or phone (+44 (0) 20 8551 7000).

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NO₂ in London


London has some of the highest levels of street pollution in the world. Oxford Street, a busy shopping zone, is one of London’s worst affected areas, with high concentrations of nitrogen dioxide (NO2) recorded. This pollutant is produced when fossil fuels are burned. Oxford Street is particularly badly affected owing to the volume of traffic on the road.

NO2, as a concentration, is measured in micrograms per cubic metre of air (µg/m³). A concentration of 1 µg/m³ means that one cubic metre of air contains one microgram of nitrogen dioxide. In a recent pollution report by Kings College London, Oxford Street was found to have an average amount of 143 micrograms of NO2 per cubic metre. The report also states that there were 1,532 hours during the year when that figure was above 200 micrograms. According to the World Health Organisation, the average level of NO2 should not exceed 200 micrograms more than 18 times a year.

The prevalence of NO2 is partly attributable to the fact that buses in London are using diesel oxidation catalysts and particle filters. In order to burn off the black soot from diesel engine emissions, exhaust gases need to reach temperatures in excess of 500°C; however, NO2 can be used to burn these sooty particles at a much lower temperature (around 200°C). As a consequence, higher amounts of NO2 are released into the atmosphere.

Ambient air monitoring is essential in large, busy cities, as high levels of pollution can cause respiratory problems and inflammation of the lungs. Transport for London (TfL) has now introduced pollution alerts, which can be found at bus stops and train stations.

If you would like further information about any of our Air Quality products, please get in touch via email ( or phone (+44 (0) 20 8551 7000).

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Introduction to Air Sampling

Air Sampler Head

Air Sampling involves drawing a known volume of air through a filter, trapping the contaminants and measuring the amount of contaminant captured. Introduction to Air Sampling

The results are usually expressed as a concentration, calculated by dividing the volume of air by the amount of contaminant captured. To calculate the volume of air, you multiply the flow rate (usually expressed in Litres Per Minute) by the duration of the sample. For this reason, the air sampler must be carefully calibrated before use to ensure the flow rate is correct. Often, multiple samples are required to provide a better understanding of the environment.

There are many different devices which can be used for air sampling:

  • Static Area samplers generally have high flow rates, meaning large volumes of air can be sampled in a short space of time. These are useful for pinpointing the source of contamination and for assessing the effectiveness of control measures.
  • Personal Air Samplers are smaller in size and have a lower flow rate. They are attached to the operator, and a sample is taken during normal working activity (usually over an 8-hour period). The sampling head is located in the worker’s breathing zone to measure how much particulate matter is inhaled.

In some industries these instruments are a legal requirement to detect the concentration of harmful airborne substances in a worker’s breathing area. These include aerosols, dusts, fumes, smokes and mists. All are a danger to health, as small particles can settle on the lining of the lungs and cause respiratory problems.

By taking air samples, employers can protect their workforce from exposure to airborne contaminants.

Introduction to Air Sampling

If you would like information on about any of air sampler products, please get in touch via email ( or by phone (+44 (0) 20 8551 7000).

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Pendulum Accessories Kit

Pendulum Feet

The Munro Stanley Pendulum Tester is built to last. Providing the instrument is regularly serviced and calibrated, it is capable of providing several decades of service with no deterioration in the quality of the results.

As with all precision instruments, it is important that the Pendulum Tester is carefully prepped prior to use. Failure to do so may result in inaccurate and unreliable readings.

In this post, we will explain how the accessories are used to set up the instrument, condition the rubber sliders and verify your results.

What are the accessories of Skid Resistance Tester?


  • Rubber Sliders
  • Aluminium Sample Holder
  • Lapping Film
  • P400 Paper
  • Float Glass
  • Pavigres Tile
  • Perspex Setting Gauge
  • Tools Wallet
  • Thermometer
  • Water Bottle

These are supplied in accordance with the UK Slip Resistance Group (UKSRG) guidelines. We recommend all users of the Pendulum obtain a copy of these useful instructions.

Rubber Sliders

Rubber Sliders are fitted onto the end of the Pendulum arm. There are three main types of slider. Each one has specific properties and must be carefully selected depending on the type of surface that you are testing.

  • TRL(55) Rubber Sliders have a hardness of 55±5 IRHD. They should be used in ‘barefoot’ pedestrian areas (e.g. bathrooms, changing rooms, swimming pools). They are also used on vehicular surfaces such as roads and runways.
  • 4S(96) Rubber Sliders have a hardness of 96±2 IRHD. They should be in ‘shod’ pedestrian areas (indoor/outdoor public spaces, pavements etc.).
  • CEN Rubber Sliders have a hardness of 53-65 IRHD.


  • Pendulum Accessories Kit

15 mm Spanner

Use the spanner to fasten the rear leg into position.

C Spanner

Once you have attached the Pendulum arm to the rotating head, tighten the retaining nut using the C Spanner.

Note: Ensure that the dowel is correctly engaged. Do not force it, as this may cause the hole to widen.

Aluminium Sample Holder

The Aluminium Sample Holder is used for conditioning the rubber sliders, verifying the Pendulum and holding floor/tile/road samples. It will prevent unwanted movement when testing samples and verification surfaces.

  • The clip is used for the P400 paper and lapping film.
  • The recess fits the Float Glass and Pavigres Tile.
  • The pegs allow you to adjust the size of the sample space.

Perspex Setting Gauge

The Setting Gauge is to set the sliding length (or ‘footprint’) of the conditioned Rubber Slider. This is the distance the rubber slider travels whilst in contact with the test surface. The sliding length should be 124±1 mm (or 76 mm if using small rubber sliders). This should be measured from the trailing edge of the metal slider plate, not the rubber itself.

The outer marks on the Setting Gauge are 125 mm apart. The two marks on the left-hand side indicate the 2 mm tolerance allowed. The distance between the right-hand mark and the middle mark is 76 mm.

Some models of the Setting Gauge also have a working edge ruler. This helps to determine when the rubber slider is too thin to use.

Rubber Slider Conditioning Surfaces

The following items are needed to prepare your rubber slider before use:

  • Sample Holder
  • Float Glass
  • P400 Conditioning Paper
  • Green Lapping Film (if using a TRL(55) Rubber Slider)
  • Pink Lapping Film (if using a 4S(96) Rubber Slider)
  • Water Spray Bottle

Preparation of the rubber sliders is crucial for good reproducibility. It ensures that each slider begins the test in the same condition. Rubber sliders must always be clean and free from contamination. Failure to follow this procedure may affect the validity of your results.

Click here for instructions on how to condition rubber sliders.

Pendulum Verification Surfaces

The Pendulum Tester should be verified at the start of each day of testing and after re-assembly or transportation. The verification procedure is an extremely important part of the testing procedure. It demonstrates to you, and all those making use of your results, that the instrument has been set up correctly and is functioning properly.

Verification is achieved by performing tests on a number of well-defined surfaces with a known Pendulum Test Value (PTV). These are given in the table below:

TRL(55) Rubber Slider 4S(96) Rubber Slider
Pink Lapping Film N/A 59-64 PTV
Float Glass 5-10 PTV 5-10 PTV
Pavigrés Tile 13-19 PTV 32-36 PTV

If these values are not obtained, you must not proceed with testing. The pendulum set-up procedure (including slider conditioning) should be re-performed, and the rubber slider should be checked for defects. If you continue to experience difficulties verifying your instrument, please contact Munro Instruments for further assistance.

Pendulum Accessories Kit

If you would like further information on using the Pendulum Tester accessories, please get in touch via email ( or by phone (+44 (0) 20 8551 7000).

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Airport Observation


Even though modern aircraft are built to withstand extreme weather, it is still important to monitor and forecast the weather in airfields and airports. The weather has a significant effect on their operation during taxiing, take-off and landing, and impacts the safety of all those on board.

Wind condition at airports

At ground level, wind observation helps to determine where, when and how aircraft take off and land. At times of high wind, it may be necessary to cease all air traffic and close the airport. This was the case in October 2016 during Hurricane Matthew when airports in Florida were forced to close.

Wind speed and wind direction should be measured using an automated sensor. The display unit should show instantaneous (real-time) measurements, as well as the 2-minute average, 10-minute average and max/min gusts. Sensors should be installed at multiple locations throughout the airfield. A back-up device, such as a handheld anemometer, is also needed in case of failure or unavailability of automated sensors.

It also necessary to measure temperature and humidity in airfields and airports, as these can affect engine performance.

Since the weather is susceptible to rapid change, meteorological observations must be recorded continuously. This should be done in accordance with national aviation standards.Using meteorological equipment

Airport Observation

If you would like further information our range of meteorological products, please get in touch via email ( or phone (+44 (0) 20 8551 7000).

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Safety in the Workplace


Employers are responsible for the health-and-safety rights of their employees.

This is enforceable in the UK under the Health and Safety at Work Act 1974. Companies who fail to comply are at risk of legal action, fines, payouts, raised insurance premiums and, in the most serious cases, imprisonment. Make sure you take health and safety seriously. Keep you employees happy, fit and able, and protect your company’s finances and reputation!

For information about how to manage slips in the workplace, get in touch via email ( or by phone (+44 (0) 20 8551 7000).