Does anyone have any recommendations for a good probe thermometer (to test water temps and rad surface temperatures)? and clamp on thermomemeters - to test flow and return pipes from a boiler/to rads?Any links/recommendations would be great.
Clamp on / Probe thermometer recommendations ...?
- Thread starter poolebybirth
- Start date
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If you want to measure surface temperatures, then an infrared thermometer is very good as it is easier to use and more accurate than a clamp on type. You can get them from Maplins. You just need to make sure you are close enough to the pipe, radiator etc, so you are just measuring the temp of the pipe and not the wall behind as well.
When you say "to test water temperature", do you mean the water coming out of the tap? You can still do this using the IR pointed at the tap spout or else you will have to buy a mercury or similar thermometer to hold in the stream of water.
I was recommended an IR thermometer.
http://www.maplin.co.uk/Module.aspx?ModuleNo=223009
Good offer too.
http://www.maplin.co.uk/Module.aspx?ModuleNo=223009
Good offer too.
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I got this one - for computer PCB refluxing. I tried using it on copper pipes but, because of copper's emissivity, they grossly under-read. When I use it on the pump (which is a coated metal), it read about 60C but on either the brass fittings or copper pipe adjacent, it read about 30C - and the reading is quite unstable.
I tried putting different sorts of tape on the pipe, which increased the displayed temperature by about 7C. What is the trick to using these IR thermometers?
the i.r. non-contact are made for surface reading e.g. radiators and work quite well on them.
for pipes you really need a contact thermometer; either the old fashioned analogue ones that you clip on, or the digital ones that use probes that you can clamp or wrap around.
for pipes you really need a contact thermometer; either the old fashioned analogue ones that you clip on, or the digital ones that use probes that you can clamp or wrap around.
Yes, so I found. Very convenient.
I suppose there must be something with which one could paint copper pipe. It would be very convenient. I tried thermal paste for computer CPUs, but it was unsuccessful!
Let us know if you find something, digital clamp ons may be very accurate, i.r. is a lot quicker.
Was just thinking of buying that IR one to balance all my rads. What if I used it on the rad right at the pipe connection? Would that work?
Or what about a temporary piece of white clip on pipe sleeve?
Or what about a temporary piece of white clip on pipe sleeve?
It works fine on the painted part of the radiator. The nearer to the pipe, the better. A clip might tend to insulate the pipe but, being adjacent to a radiator, you could check for yourself.
I have to say that I have always found IR thermometers a total waste of time for anything that needs an accurate result. They can read up to 10° low.
The only way to get an accurate result is with a contact TC probe for boiler measurements and particularly fault finding.
The IR types are OK for rad balancing and temperature checking because you dont need an exact temperature and the error is similar on all the rads and different parts.
The IR types are also very good for finding heat loss blackspots where insulation needs to be improved.
Tony
The only way to get an accurate result is with a contact TC probe for boiler measurements and particularly fault finding.
The IR types are OK for rad balancing and temperature checking because you dont need an exact temperature and the error is similar on all the rads and different parts.
The IR types are also very good for finding heat loss blackspots where insulation needs to be improved.
Tony
That could be due to the emissivity of the surface being measured. Most IR thermometers are calibrated for an emissivity of 0.95 (a matt black body has an emissivity of 1). The emissivity of copper can be as low as 0.03. The usual dodge is to wrap the pipe in some black insulating tap and read off the tape.
The second problem with IR's is the distance:spot ratio; this measures the diameter of the area measured compared to the distance from the object. If the ratio is 10: 1 then, if you are 1 metre from the surface, you will be measuring over an area of 10cm diameter. Not too important if you are pointing it at a wall or the middle of a radiator. But if you are pointing at a rad pipe, it will be averaging the temperature of the pipe and the wall behind it. You will need to be less than 10cm from then pipe to make sure you are only measuring the pipe.
The last problem is the laser beam. This is usually some way below the IR sensor so, when you are very close to a heating pipe, if you have the laser beam hitting the pipe, the sensor may not be reading the pipe temperature.
I didn't have much success with this.
Good point. I get as close as practical.
Another good point - but you can orientate the thermometer so that laser and sensor are along the pipe.
TPI 323 - Differential Thermometer with T1 T2 connections for clamps for pipes and a Testo 810 (IR) for rough air and contact temps on rad's 
Its not important which of the short comings of an IR thermostat apply in any particular application.
Its just that they are not accurate enough to be useful for professional applications where its important to have an accurate measurment.
Just about good enough for comparative measurements on rads as long as those measurements are not going to be used for setting up boilers.
Tony
Its just that they are not accurate enough to be useful for professional applications where its important to have an accurate measurment.
Just about good enough for comparative measurements on rads as long as those measurements are not going to be used for setting up boilers.
Tony
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