All Radiator Thermometers are not the same…

I am sure regular readers of my blog (hi Mum) will be most disappointed to learn that I have no amusing thermometer based anecdotes this time as I have run out!

I haven’t actually run out, I’ve got loads.

I just thought I would try and be a bit more informative this time with an article about radiator thermometers – and keeping warm and saving money is no laughing matter!

Central Heating and Radiator Thermometers

Via our on-line thermometer shop we receive regular enquiries from both homeowners and tradesmen looking for a suitable thermometer capable of checking the temperatures of both radiators and central heating pipes.

Whilst we find that there is a high demand for this type of instrument (especially recently during the extremely cold spell we have had), it is a corner of the market that is very badly served by thermometer manufacturers.

We have found that there is very little choice, and what is available is not really accurate enough for the job in hand.

There are generally two models available, both of which are bi-metal dial type:

  • pipe thermometer – complete with ‘spring clip’ for attaching to pipe work.
  • magnetic surface thermometer – complete with magnetic pad for mounting on to ferrous metals.

There are inherent problems with both these thermometers. Firstly, bi-metal type thermometers aren’t particularly accurate which is not helpful when trying to ‘balance’ radiator temperatures. The spring clips on the pipe thermometers are very tricky to attach and aren’t very good at holding the thermometer in a fixed position.

The magnetic thermometers are accurate enough, but will only work on ferrous metal (steel radiators only), and even then, only on radiators that haven’t had 10 coats of paint applied over the years!

We as thermometer sellers have found the increase in demand for this type of temperature monitoring, countered by a lack of choice of instrument, increasingly frustrating.

The Ideal Heating System Thermometer?

With this in mind we have taken it upon ourselves to put together a custom made kit to cater specifically to this market. We wanted one thermometer that could accurately take temperatures of both pipe work and radiators, and this is what we have come up with:


We have combined an accurate digital thermometer with an ‘industrial’ type clamp probe which can attach to both radiators and heating pipes.

This thermometer has that added advantage of accepting a wide range of readily available probes which means it can be used for a vast range of other temperature monitoring tasks, making it a very versatile and cost effective proposition. All for just a few pounds more than the bi-metal type instruments.

As you’d expect, this accurate pipe clamp thermometer kit is exclusively available from the Thermometer Superstore, so why not visit us for more information?

A Few Energy Saving Tips

As this is a more serious post, let’s finish it with a few helpful tips regards being green, energy efficient and saving money all at the same time:

  • Turn down the radiators in any spare rooms. After all, why pay for a warm room with nobody in it?
  • If you have one, turn your room thermostat down by just 1ºC and you could save quite a bit of money without ever noticing the difference.
  • Be sure to bleed your radiators at least once a year. Radiators are much more efficient when hot water can flow into every part of them.
  • If you have an adjustable thermostat for your hot water you should set it to no hotter than 60°C. Any higher is a waste of energy and could scald.
  • Remember to turn down your heating when you’re going away for any length of time. 5°C – 10°C should be plenty to prevent interior pipes freezing.
Posted in Digital Thermometers, Electronic Thermometers, Heating System Thermometers, Radiator Thermometers | Tagged , , , , , , , , | Leave a comment

The Right Thermometer for the Job

Following on from a blog I wrote a few weeks ago regarding the misuse of an infra-red ear thermometer I thought I would pursue the subject of ‘right tool for the job’ in a little more detail.

As you may or may not know my ‘proper’ job is as a purveyor of temperature recording equipment (what a coincidence!) to both business and home users.

In my daily tiptoe through the wacky world of online retail I regularly get asked if a particular thermometer can be used for a purpose it was never intended, designed or more importantly, suitable for.

Sub-Aqua Dentistry?

I was contacted recently by a manager of a dental surgery who asked if a wall mounted workplace thermometer would be suitable for checking water temperature.

I was tempted to ask if this particular dental surgery was at the forefront of some sort of cutting edge underwater dental technique but managed to resist and instead steered the bewildered customer (in my usual professional manner) towards a more suitable instrument.

Incidentally (pardon the pun) I would imagine that using the underwater technique could save dentists a fortune on mouth wash!

Out of interest, we would usually recommend a fast response, waterproof probe type thermometer for checking running water and either a floating bath thermometer or bath scoop thermometer (with built in water scoop to collect a sample of water to monitor) for standing water.

Another 50p for the Meter?

I also had an enquiry a few weeks ago from a procurement manager for a large chain of nursing homes, asking if our fridge / freezer dial thermometers would be suitable for use in resident’s rooms. A cynical and suspicious person (such as my good self), may well be suspecting foul play at this point. The thermometer in question does record temps right down to -40°C. Granted they don’t actually have a ‘rigor mortis zone’, but one could be forgiven for wondering why someone needed a room thermometer that recorded such extreme temperatures.

To my great relief it turned out to be merely a case of ignorance and our customer was thrilled to find out that we supplied a hypothermia thermometer complete with coloured zones displaying safe and unsafe room temperatures. Another satisfied customer!

No fun being a dog?

Finally I was contacted some time ago buy a guy who asked if our beer brewing thermometer would be suitable as a rectal thermometer for his dog.

This is not quite as bizarre as it first seems, as this thermometer is a traditional spirit filled glass thermometer similar to the ones vets use, so in theory it would be OK, if used carefully (as these are 12” in length!). Although not an expert in home brewing myself I did suggest that the use of a good old barrel or vat may have been more appropriate method of fermenting his hops!

The Moral of this Story…

The moral of the blog this time is that although many thermometers can be used for applications other than the one they were designed for, it is generally best to use an instrument that is most suitable for the task in hand. There is little point in monitoring the temperature of something if the readings cannot be relied on to be accurate.

If in doubt, ask advice – please!

Posted in Bathroom Thermometers, Fridge Freezer Thermometers, Home Brewing Thermometers, Workplace Thermometers | Tagged , , , , , , , | Leave a comment

Temperature of Cooked Chicken

This post is a response to a comment on my Ask me a temperature related question… post. If you have any questions related to the world of temperature or thermometers, post it on there and I’ll endeavour to answer it.

The Question

I had a bad experience recently cooking chicken, whereby a few members of my family fell ill.

I’m not keen to repeat my mistake. What temperature should I be cooking chicken to? And how do I test the temperature?

Any help gratefully received…

My Answer

To be cooked properly the inside of the chicken must reach 85°C at its thickest part.

If you’re worried about food poisoning, your best bet is to use a Meat or Poultry Thermometer with a probe which you insert into the thickest part of the chicken. They’re generally marked to show temperatures for various types of meat, poultry and fish.

For something simpler, you could try a Pop-Up Poultry Thermometer. You simply insert the thermometer into the thickest part of the turkey or chicken before cooking and cook it in the oven as usual. The thermometer pops up when the bird has been cooked to the correct temperature of 85°C.

They’re manufactured from food-grade plastic so are perfectly safe.

For a really detailed article on cooking poultry, take a look at this Safer Christmas Eating article on one of the soon to be defunct Food Standards Agency websites.

Hope that helps!

Posted in Frequently Asked Questions, Meat Thermometers, Oven Thermometers, Poultry Thermometers | Tagged , , | Leave a comment

Ask me a temperature related question…

Not your usual blog post title I know. Rather than telling you something, I’m asking if there’s anything you want to know. Do I hear you say “¿Qué”? Well maybe not… Unless you’re Spanish or doing an impersonation of Manuel from Fawlty Towers.

Let me explain.  I’m TheThermometerGuy and for a few weeks now, I’ve been writing a blog about my specialist subject (thermometers if you can’t guess!). Don’t laugh, but as I work with thermometers everyday I’d decided to commit some of my knowledge to a blog for others to benefit from.

Thus far I’ve been putting together articles that I think might be of interest, but then I thought, hey, why not ask the blogging world what they want to read about.

So seriously, ask me something related to temperature on any of the following subjects: aquariums, babies, bath tubs, beer making, making candy, cooking chicken, childcare, children, chilled cabinets, cooking, fertility, fever, food preparation / storage, fridges, frying, fudge making, gardening, greenhouses, healthcare, heating systems, home brewing, hvac, hypothermia, jam making, cooking meat, microwaves, ovens, ovulation, ponds, poultry, reptiles, snakes, soil, swimming pools, terrariums, toffee making, tropical fish, turtles, wine making, workplaces, yogurt making and anything else you can think of.

It’s amazing what you learn when you’re working with thermometers all day. Admittedly though, if you ask me, I’d have to look up the temperature of Saturn!

Post a question in the comments on this blog and I’ll post the answer in a reply or if it warrants it, as a new post on my blog with a link back to yourself.

So over to you guys…

Er… Obviously, I realise this idea might not work so don’t worry regular readers, I’m already planning my next post.

Posted in Frequently Asked Questions | Tagged , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , | 3 Comments

No Daddy, It Doesn’t Go There!!

Whilst doing some research for my latest foray into the fascinating world of thermometers (don’t laugh – it is my world), I found another story that amused and disturbed me in equal measure.

Apparently a father, who suspected his poorly young son was developing a fever decided, quite understandably, to take the little fella’s temperature. So far so good!

So he decides to use an infrared ear thermometer he finds in the medicine cabinet. Everything still good! These are a reliable choice for measuring body temperature. But…

Unfortunately due to the fact he was a) a man or b) a little on the simple side, he didn’t read the instructions.

The poor child then had the thermometer inserted into an orifice where it was probably least welcome – er, that’s his bum for those of you who are unsure to where I am referring.

What does this anecdote tell us?

  • Unless all other options are unavailable, never leave a man alone with a sick baby
  • Always read the instructions
  • If in doubt, read the instructions again
  • If still in doubt seek professional (or at the very least sane) help

Infrared thermometers are intended to be non-contact, non invasive instruments.

Having a thermometer shaped a bit like a hand gun stuck where the sun don’t shine must register near the top of anyone’s idea of invasive contact!

Now for the informative stuff:

Body temperature can be monitored with infrared ear thermometers, which measure the infrared energy emitted from the patient’s eardrum. A short tube with a protective sleeve is inserted into the ear, and a shutter is opened to allow radiation from the tympanic membrane to fall on an infrared detector for a period which is typically from 0.1 to 0.3 seconds in the varieties surveyed. The device beeps when data collection is completed and a read out of temperature is produced on an LCD screen.

This kind of temperature reading from the eardrum has been found to be a clinically reliable indicator of body core temperature. The eardrum is located close to the hypothalmus, which is the body’s temperature regulator. The membrane itself is thin and almost transparent in the visible, so you would presume that it reliably tracks the temperature inside the membrane so that the infrared energy it emits gives a good indication of the inside temperature.

All joking aside, most ear thermometers are extremely simple to use, and have a single button operation.

You just place the thermometer tube in the ear opening and press the button. When the thermometer beeps, the monitoring is complete and the reading is displayed.

Temperature measurement range is usually between around 34°C and 42°C. Most instruments are supplied with a set of replaceable probe tip covers for hygiene reasons.

Just remember to read those instructions…

Posted in Ear Thermometers, Healthcare Thermometers, Infrared Thermometers, Thermometers | Tagged , , , , , , , , | Leave a comment

I did NOT stab anyone with a Meat Thermometer

I wouldn’t want people to think that I was in any way vain but whilst Googling “Thermometer Guy” (don’t laugh – we’ve all Googled our name haven’t  we? No, just me then!) I came across this article in the US press:

 “Up in Lancaster over the weekend, a man who asked a woman to stop talking on her cell phone during a movie was stabbed in the neck with a meat thermometer by the woman’s apparent enraged boyfriend and another friend (yes, how dare he ask for silence during a movie, right? Geeeeez.). The man is expected to survive and two others who came to his aid were also injured during the incident at the Cinemark 22 theatre, according to KTLA. L.A. County Sheriff’s say there are two male black suspects in the case that got away.”

I need it to be on record that I am not that thermometer guy.

I admit that I do indeed live in Lancaster, but that is Lancaster UK, a completely different place entirely from the one above.

I would also like it to be known that I neither condone nor recommend the use of meat thermometers or indeed any type of temperature measuring equipment to resolve cinematic based issues. For what it is worth my choice of weapon would be popcorn. One’s point can be made without anyone getting too badly hurt, in the true English tradition.

For more information on what happened next, take a look at this site. For more info on the correct use of meat thermometers see below.

Meat Thermometers

A meat thermometer has a metal probe with a sharp point which is designed to be inserted into the meat, and can have a dial or digital display. Some dial type thermometers show the temperature only, whilst others also have markings to indicate when different kinds of meat are cooked to a specified degree (e.g., “beef medium rare”).

Meat thermometers are usually designed to have the probe left in the meat during the cooking process. Dial thermometers use a bimetallic strip which rotates a needle which shows the temperature on a dial. With these, the whole thermometer can be left inside the oven during cooking.

Digital thermometers however, use an electronic sensor in the probe, which is connected by a flexible heat-resistant cable to the digital display unit. The probe is inserted in the meat, and the cable comes out of the oven (oven seals are flexible enough to allow this without damage) and is connected to the display. This type of instrument often has the facility to set an audible alarm when the desired temperature is reached.

Please note that if the complete digital thermometer is placed in a hot oven, it will melt and you will be left with a foul smelling sticky mess in the bottom of your oven. This will be tricky to clean up when the oven is hot, unless you have access to welding gloves and an industrial scraper, and virtually impossible to remove once cold. In short try to avoid this situation.

This less than desirable, but schoolboy error happens more often than you may think, usually to men who don’t read instructions before using new equipment!

A low-cost alternative designed specifically for poultry is the pop-up poultry thermometer, which uses a spring held in by a soft material that “pops up” when the meat reaches a set temperature. To their credit, these are very hard to use incorrectly and practically useless for hand-to-hand combat!

Coming Soon…

Please watch out for my next riveting blog – this time on Infra-red Ear Thermometers. You can hardly wait right??

Posted in Digital Thermometers, Meat Thermometers, Oven Thermometers, Probes, Thermometers | Tagged , , , , , , , , | 1 Comment

A Bit Lighter?

Okay, last night the wife looked at my blog and accused me of being over-informative and under-interesting, saying the blog was in definite need of lightening up a bit!

I don’t like to concede that she’s right, but to that end, there’s better blogging on the way.

From now on, I will attempt to entertain as well as educate. Watch this space!

Posted in Thermometers | Tagged | Leave a comment

Testing Thermometer Accuracy (aka Calibration)

A thermometer’s accuracy is vital if the temperature readings it produces are to be relied upon. For this reason calibration, or the regular checking of a thermometer’s accuracy, should always be incorporated into any relevant business safety system.

The type of calibration check varies, depending upon factors such as the size of the business and how vital the readings being taken are to the performance of the business.

The Cheap Option

In its simplest form, the calibration of a digital thermometer can be done by measuring known temperatures such as water at melting and boiling points, 0°C and 100°C respectively.

To do this you would place some crushed ice and a little water in a container and insert the thermometer’s probe. Allow time for the instrument to stabilise and the reading the thermometer should give should be 0°C ±0.5°C.

Repeat the process using boiling water and this time a reading of 100°C ±0.5°C should be achieved. It should be born in mind, however, that the temperature of the water will drop quickly and therefore the reading should be taken as soon as possible. Care should be taken to avoid scalding.

Reference Thermometers

A better and more reliable calibration system involves the use of at least two thermometers. One of the instruments should be a reference thermometer, which should be tested annually by a UKAS accredited laboratory to ensure it is reading to accurately.

It is recommended that this instrument be kept specifically for calibration testing and not for daily or regular process testing. Other thermometers can then be checked against the tested instrument and the temperature readings compared. Ideally, this should always be done as soon as possible after the instrument has been certified.

The two or more probes should be placed together (an elastic band can hold the probes together securely) and placed in the water. Again testing can be done in melting ice and hot water so that the instrument’s accuracy is being checked over a temperature range. The probes should be allowed to stand for at least 30 seconds, and then steadily stirred in the water for at least another 30 seconds. The stirring should ensure that the water is the same, uniform temperature throughout, and will improve the speed of response of the readings.

If the two instruments have a claimed accuracy of 0.5°C the temperature readings of both should read the same ±1°C. This tolerance allows each of the instruments to be at the extreme of their accuracy tolerances, i.e. if one is reading 0.5°C high and the other 0.5°C low, there will be an apparent difference of 1.0°C.

Testing accuracy can be improved further using a comparator combined with a certified reference thermometer which has an accuracy of ±0.2°C. Alternatively systems can be checked by immersion in a stirred water bath or even a mini calibration bath and comparing the temperature against another thermometer that you know is accurate i.e. has a current UKAS certificate.

Test Caps

Where an instrument has a socket for a probe, calibrated thermometer test caps are available. These may be used on a regular basis to monitor the performance of the instrument. Test caps are available for Thermocouple, Thermistor and PT100 instruments and in a range of temperatures. The caps are simply inserted into the probe socket in place of the normal probe and the instrument should give a reading equivalent to the test cap’s rating.

Thermometer Checkers, which also act as probes at three different temperatures, and are also available and are used in the same way as test caps. However, as with test caps, the checker will only show the accuracy of the instrument. It will not test the accuracy of the probe and therefore to ensure confidence in a measurement, the combined system of instrument and probe should be calibrated.

Posted in Dataloggers, Digital Thermometers, Probes, Reference Thermometers, Test Caps | Tagged , , , , , , | Leave a comment

Measuring Food Temperature with a Digital Thermometer

Typically, digital thermometers are easy to use and quick to respond. They generally consist of a probe, a display and an electronic means of converting the data received from the probe detector into a displayed reading.

However, despite being easy to use, there are a few things you need to be aware of when using one to measure the temperature of food.

The Thermometer Itself

The first thing to remember is that a thermometer measures its own temperature as well. This means that the probe must be allowed to reach the temperature of the substance or object of which you are measuring.

Inside the probe is a detector which relays information to the electronics of the thermometer. When you insert the probe into a substance, for example hot soup, the probe will start to heat up.

If the probe is large and thick, it will take longer to heat up and the detector will therefore take a long time to react. In this instance the display will show a slowly increasing temperature. This makes the determination that the thermometer has reached the final temperature more difficult.

A thin probe will react more quickly, reach the appropriate temperature, and remain steady if the temperature of the substance is steady.

Where to take the Reading

It is very unlikely that the whole of an object or substance will be the same temperature throughout. You need to decide therefore where to insert the probe to take the temperature.

In a pan of soup on a stove, the bottom of the pan and the soup immediately adjacent to it will be very hot, whilst the middle of the soup could be cold. This is particularly true when reheating frozen liquids.

To get a better reading, the liquid should be thoroughly stirred and the temperature taken whilst the pan is stirred. This will then give the average temperature of the whole content. Remember though, if the probe touches the bottom of the pan, your reading will tell you the temperature of the pan, not that of the soup.

When cooking food in an oven, generally it is being heated from the outside and therefore the temperature must be taken in the centre of the object.

It may be that the item being heated has different densities and different thicknesses, which will take different times to heat. As an example, the bones and thickness of meat in a turkey leg can be a problem and therefore the temperature probe should be inserted into the thickest part of the leg.

Similarly when cooking joints of meat of varying thickness, it is the thickest part should be tested.

If you are reheating food in a microwave, the item can often be heated in different areas, thus resulting in the development of hot-spots. It is essential that resting time is allowed for in the process, to allow the heat to even out, and accurate temperatures to be taken.

Infrared is not Ideal

The development of infrared thermometers has revolutionised temperature monitoring – but it must be appreciated that an infrared thermometer only measures the surface temperature that it sees i.e. the outside of an object. The ideal combination therefore is an infrared thermometer with a probe facility.

The Length of a Reading

A digital thermometer may show temperatures at 1°C or 0.1° intervals. If the reading does not change for 20 seconds on a 1°C instrument or 5 seconds on a 0.1°C instrument you can be confident that a satisfactory reading has been achieved. Obviously this will require a longer time if you need a more accurate reading.

Avoiding Cross-Contamination

The probing of foods can involve cross-contamination. Probes should be wiped clean after each measurement with an anti-bacterial probe wipe, and ideally different probes should be used for highly contaminated foods such as raw poultry.

Your Responsibilities

Temperature requirements for commercial preparation of foodstuffs can be found in the Food Safety (Temperature Control) Regulations, England & Wales.

Temperatures should be monitored and recorded on a regular basis to show due diligence. To save time and effort, dataloggers are a useful tool for keeping a record of storage temperatures.

Posted in Digital Thermometers, Electronic Thermometers, Thermometers | Tagged , , , , , , , , , , , , , , , , , , , , | Leave a comment

What is the Emissivity of XYZ?

Emissivity is a measure of the efficiency in which a surface emits thermal energy. It is defined as the fraction of energy being emitted relative to that emitted by a thermally black surface (a black body). A black body is a material that is a perfect emitter of heat energy and has an emissivity value of 1. A material with an emissivity value of 0 would be considered a perfect thermal mirror.

For example, if an object had the potential to emit 100 units of energy but only emits 90 units in the real world, then that object would have an emissivity value of 0.90. In the real world there are no perfect black bodies and very few perfect infrared mirrors so most objects have an emissivity between 0 and 1.

Emissivity Values

Below is a list of approximate (see Accuracy below) emissivity values for most materials you might want to measure the temperature of:

  • Aluminium: anodised – 0.77
  • Aluminium: polished – 0.05
  • Asbestos: board – 0.96
  • Asbestos: fabric – 0.78
  • Asbestos: paper – 0.93
  • Asbestos: slate – 0.96
  • Brass: highly polished – 0.03
  • Brass: oxidized – 0.61
  • Brick: common – 0.81-0.86
  • Brick: common, red – 0.93
  • Brick: facing, red – 0.92
  • Brick: fireclay – 0.75
  • Brick: masonry – 0.94
  • Brick: red – 0.90
  • Carbon: candle soot – 0.95
  • Carbon: graphite, filed surface – 0.98
  • Carbon: purified – 0.80
  • Cement: – 0.54
  • Charcoal: powder – 0.96
  • Chipboard: untreated – 0.90
  • Chromium: polished – 0.10
  • Clay: fired – 0.91
  • Concrete – 0.92
  • Concrete: dry – 0.95
  • Concrete: rough – 0.92-0.97
  • Copper: polished – 0.05
  • Copper: oxidized – 0.65
  • Enamel: lacquer – 0.90
  • Fabric: Hessian, green – 0.88
  • Fabric: Hessian, uncoloured – 0.87
  • Fibreglass – 0.75
  • Fibre board: porous, untreated – 0.85
  • Fibre board: hard, untreated – 0.85
  • Filler: white – 0.88
  • Firebrick – 0.68
  • Formica – 0.94
  • Galvanized Pipe -0.46
  • Glass – 0.92
  • Glass: chemical ware (partly transparent) – 0.97
  • Glass: frosted – 0.96
  • Glass: frosted – 0.70
  • Glass: polished plate – 0.94
  • Granite: natural surface – 0.96
  • Graphite: powder – 0.97
  • Gravel – 0.28
  • Gypsum – 0.08
  • Hardwood: across grain – 0.82
  • Hardwood: along grain – 0.68-.73
  • Ice – 0.97
  • Iron: heavily rusted – 0.91-.96
  • Lacquer: bakelite – 0.93
  • Lacquer: dull black – 0.97
  • Lampblack – 0.96
  • Limestone: natural surface – 0.96
  • Mortar – 0.87
  • Mortar: dry – 0.94
  • P.V.C. – 0.91-.93
  • Paint: aluminium – 0.45
  • Paint, oil: average of 16 colours – 0.94
  • Paint: oil, black, flat – 0.94
  • Paint: oil, black, gloss – 0.92
  • Paint: oil, grey, flat – 0.97
  • Paint: oil, grey, gloss – 0.94
  • Paint: oil, various colours – 0.94
  • Paint: plastic, black – 0.95
  • Paint: plastic, white – 0.84
  • Paper: black – 0.90
  • Paper: black, dull – 0.94
  • Paper: black, shiny – 0.90
  • Paper: cardboard box – 0.81
  • Paper: green – 0.85
  • Paper: red – 0.76
  • Paper: white – 0.68
  • Paper: white bond – 0.93
  • Paper: yellow – 0.72
  • Paper: tar – 0.92
  • Pipes: glazed – 0.83
  • Plaster – 0.86-.90
  • Plaster: rough coat – 0.91
  • Plasterboard: untreated – 0.90
  • Plastic: acrylic, clear – 0.94
  • Plastic: black – 0.95
  • Plastic: white – 0.84
  • Plastic paper: red – 0.94
  • Plastic paper: white – 0.84
  • Plexiglass: Perpex – 0.86
  • Plywood – 0.83-.98
  • Plywood: commercial, smooth finish, dry – 0.82
  • Plywood: untreated – 0.83
  • Polypropylene – 0.97
  • Porcelain: glazed – 0.92
  • Quartz – 0.93
  • Redwood: wrought, untreated – 0.83
  • Redwood: unwrought, untreated – 0.84
  • Rubber – 0.95
  • Rubber: stopper, black – 0.97
  • Sand – 0.90
  • Skin, human – 0.98
  • Snow – 0.80
  • Soil: dry – 0.92
  • Soil: frozen – 0.93
  • Soil: saturated with water – 0.95
  • Stainless Steel – 0.59
  • Stainless Plate – 0.34
  • Steel: galvanized – 0.28
  • Steel: rolled freshly – 0.24
  • Styrofoam: insulation – 0.60
  • Tape: electrical, insulating, black – 0.97
  • Tape: masking – 0.92
  • Tile: floor, asbestos – 0.94
  • Tile: glazed – 0.94
  • Tin: burnished – 0.05
  • Tin: commercial tin-plated sheet iron – 0.06
  • Varnish: flat – 0.93
  • Wallpaper: slight pattern, light grey – 0.85
  • Wallpaper: slight pattern, red – 0.90
  • Water: – 0.95
  • Water: distilled – 0.95
  • Water: ice, smooth – 0.96
  • Water: frost crystals – 0.98
  • Water: snow – 0.85
  • Wood: planed – 0.90
  • Wood: panelling, light finish – 0.87
  • Wood: spruce, polished, dray – 0.86

Source: Electronic Intstruments Ltd (ETI)


The accuracy of the emissivity figures listed above is almost impossible to guarantee as the emissivity of a surface will not only alter with regard to texture and colour, but also with its actual temperature at the time of measurement.

It is recommend, in the first instance, that you compare measurements found with an accurate surface probe or wire probe, and then your infrared thermometer can be adjusted to match the correct emissivity and used for subsequent measurements.

Posted in Emissivity, Infrared Thermometers | Tagged , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , | Leave a comment