Pipe thermometers

[Harry Bloomfield]

Yes, I do have a pair of old bi-metal pipe thermometers around, but I have in mind to seek out something a little more up to date and with better accuracy. Something like this...

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Separate sensor at the end of a wire and I was thinking to attach them to the pipes with pipe insulation - pipe insulation over the top, to ensure they pick up pipe temperature rather than air temperature. Reasons please why that wouldn't work better than the traditional pipe thermometers?

 

[RandomGrinch]

What do you intend to do with the readings?
Are you going to datalog, or just visually monitor them?

For experiments, we would use thermocouples (mounted with some thermal transfer compound) connected to a data logging digital thermometer.

Alternatively, you could use an IR thermometer and just point it at the pipes?

 

[JonathanM]

I have an IR thermometer. When I point it an unpainted copper pipes which are about 70 degrees, it gives a reading of about 35. Is there anyway to make it give a proper reading?

 

[RandomGrinch]

I have an IR thermometer. When I point it an unpainted copper pipes which are about 70 degrees, it gives a reading of about 35. Is there anyway to make it give a proper reading?

Using IR to measure the temperature of shiny surfaces can be troublesome!
I'm used to using IR cameras, rather than thermometers, but a quick and dirty solution may be to paint a small patch of matt black paint on the pipe and point the thermometer there.
It may also be worth checking the calibration of your thermometer, by pointing it at objects of known temperature - ice water and just boiled water for example.

 

[JonathanM]

Using IR to measure the temperature of shiny surfaces can be troublesome!
I'm used to using IR cameras, rather than thermometers, but a quick and dirty solution may be to paint a small patch of matt black paint on the pipe and point the thermometer there.
It may also be worth checking the calibration of your thermometer, by pointing it at objects of known temperature - ice water and just boiled water for example.

The paint is a good idea!

I did some basic calibration, and most surfaces seem OK. Just the shiny copper was so far out I knew it couldn't be true. Radiators at the same time were just below 70.

 

[ericmark]

I have an IR thermometer. When I point it an unpainted copper pipes which are about 70 degrees, it gives a reading of about 35. Is there anyway to make it give a proper reading?

Your not the only one to have problems, the lock shield on a radiator should be set to give approx 15ºC between feed and return, wife bought a point and read thermometer at start of Colvid, it has the option of reading the temperatures of babies bottles, so thought great, use it to set radiators, but the reading was not stable enough.

I have thermostats for beer brewing with the same type of sensor shown for the thermometer, and I use a buggy cord and a sponge to hold it to the fermenter, and it works fine. Before I used a stick on strip, which measures the average of fermenter and room air, can't really do anything else, to read it needs to be uncovered, OK if room and fermenter temperature is close, but when room cools it was showing low, and when room heated up showing high.

 

[Harry Bloomfield]

I have an IR thermometer. When I point it an unpainted copper pipes which are about 70 degrees, it gives a reading of about 35. Is there anyway to make it give a proper reading?

I find my IR fairly accurate, but you can improve them by sticking black electrical tape on the surface.

To measure flowing water temperature, as from a tap, I use a thing bit of metal, with a layer of black tape.

 

[Harry Bloomfield]

I have thermostats for beer brewing with the same type of sensor shown for the thermometer, and I use a buggy cord and a sponge to hold it to the fermenter, and it works fine. Before I used a stick on strip, which measures the average of fermenter and room air, can't really do anything else, to read it needs to be uncovered, OK if room and fermenter temperature is close, but when room cools it was showing low, and when room heated up showing high.

I use one similar for my 5gallon wine fermenter, except it controls the heated plate under the FV - using a bird whatsit look a like. I have the sensor taped to the side of FV, then a cut down foam intended for camping/bed, with a bungy cord pulling it close.

 

[Harry Bloomfield]

What do you intend to do with the readings?
Are you going to datalog, or just visually monitor them?

No particular reason just to visually monitor to see what it's doing. The boiler itself displays its flow temperature, but a comparison on the actual pipes would be interesting, to maybe help tweak the pump speed.

 

[Harry Bloomfield]

I decided to order a pair of them and they turned up this morning. They each use 2x LR44 cells - at room temperature they have settled to show +19.0C and the other +19.1C which is in reasonable agreement with my room thermometer. So very useable as a pair of accurate pipe thermometers.

 

[JonathanM]

I find my IR fairly accurate, but you can improve them by sticking black electrical tape on the surface.

To measure flowing water temperature, as from a tap, I use a thing bit of metal, with a layer of black tape.

I tried the black electrical tape but it still didn't work. I eventually realised that the laser pointer was miles out and it was still reading shiny copper!

Now getting sensible flow and return readings by deliberately aiming the dot high and to the right of the tape.

 

[Harry Bloomfield]

I tried the black electrical tape but it still didn't work. I eventually realised that the laser pointer was miles out and it was still reading shiny copper!

Now getting sensible flow and return readings by deliberately aiming the dot high and to the right of the tape.

There is bound to be some parallax error between laser and the sensor, especially if you are very close to the item.