Over two years ago there was a post about infrared thermometers.

La Pavoni + IR Thermometer

This is a general thing, not just La Pavoni. There have been other posts on this topic, but perhaps an update is in order.

These things are now extremely inexpensive. They require simply that the infrared emissivity of the object whose temperature is being measured have high infrared emissivity. This means bare metal and certain other materials work VERY poorly. Infrared thermometers have an emissivity correction system that can be applied, but the emissivity of bare metal is so poor that one cannot accurately measure temperatures of bare metallic objects.

Attaching sensors to espresso machines results in messy wires running everywhere, and, unless the sensors be attached properly they can give faulty measurements.

The polymers used by La Pavoni and others to coat brass or copper has very high emissivity. This can be checked by measuring temperature with an IR thermometer and at the same time with another device. If the other device read higher it means the emissivity is low. If the other device read lower it probably means the other device is not in proper contact.

For chrome plated or bare copper or brass one must remember that most tape materials are made of polymers, natural or otherwise, and that these materials are highly IR emissive. Simply placing pieces of tape on the sites on a machine that one wants to measure lets one explore temperature. I use clear tape.

Remember many "real" brass and copper La Pavoni machines have bare boilers without an oxide coat. These develop an oxide coat, but still not enough to make infrared thermometers read them accurately.

With my 1963-4 first generation machine I like to measure the temperature in the centre of the vertical part of the group. To me espresso from this machine seems best with this temperature a bit below 90.

With my 1978 and 1999 second generation machines I like to measure the temperature on the flare just below the vertical part of the group. To my taste ideal is again around 90. (The design of second generation machines results in the upper vertical part of the group being close to boiler temperature when it is properly bled.)

Still I remain convinced that the very best temperature measurement on first and third generation La Pavoni machines is to have a deep thermometer well in the rod that moves the piston. (From the design it probably makes little sense to do this with the second generation machines because of the live steam that is in the top of the group. In a properly bled group one of these machines would always read boiler temperature when read in this manner!) Stainless steel might not be the ideal material for this because of its extreme low conductivity. The thermometer well would have to be deep enough so that the probe would be just at the top of the piston. One could then simply insert a thermometer into the well without obnoxious wires! The moduli of brass are sufficiently high so that brass could be used for this, and it is extremely easy to machine.

I have considered infrared but for now am settled in with a k type probe.

My reasons were more of practical use for my set up. I want hands off operation. K probes can be attached and turned on/off, i would have to hold the ir. I considered making a box stand and easy on/off switch for it but then i realized that my Pavoni slid around a bit on my base and just slightly off would mean having to check alignment everytime sonce i would be aiming for a small strip of tape. Then i bracketed the Pavoni stationary on the base but even with new rubber feet the base sometimes moves a tad this way or that for a variety of reasons- sometimes intentionally. In the end i decided i would prefer the simplicity of a ktype probe and just work in simple improvements on that. If you had a convenient hands free way to see the temp using ir and the pavoni was kept perfectly positioned i would prefer to try ir

A second and perhaps more problematic issue is one that i have recently been working with. The measurement of one single point on the pipe may not always be perfectly consistent with overall pipe temperature. I posted today about laying 3/4 of an inch of the wire before the bead on the pipe as well and how this seems to be giving me more steady readings that would appear more align with the pipes overall average temperature. I would imagine that as the pipe fluctuates temperature getting the reading of one single small point might-i am not sure- be somewhat less consistent with overall average pipe temperature than having the larger pipe surface area affect the probe reading.

I typically do not measure temperature at all, unless dialing in new coffee. The boiler temp getting to the correct point is pretty predicatble as the room temperature and heating power are and I almost always start with the boiler filled to the same point.
With the faemina it is quite easy to let the IR thermometer 'look through the window', (the big round sighglass) and move it's 'beam up and down the inside and read off the average or highest temp (depending on what you like best as measurement, I tend to go with the avg)) on the IR gun.

Hehe...i think your faemina group is so stable and consistent you just dont have to worry about it:) but i am pretty sure he was referencing group temp as most of us pavoni users have installed pressure gauges (though i still find it important i could probably get pretty close based on sounds now.)

IR thermometer with clear piece of tape is something I discovered for myself about 6 months ago, and I use it on most of my levers. It's nice to have one gun that can basically check wherever you want.

I left my messy wired up thermoprobes on one of them however because it gave it a really cool "mad sciency" vibe to it.

The faemina is quite stable, I'll give you that.
I love the IR gun in the kitchen, about everyone seeing me measure my espresso machine, modified pizza oven etc with it thinks I'm a geek anyway so no issues there

My IR gun came with a K probe with which you can measure directly or use it to set the Emissivity coefficient which normally is at 0,95 ( not any good for most surfaces)... Has anyone cared to do that ? (I did not bother yet as the measurement through the sighglass is close enough to the temp of flushed water as measured by the K probe)

Does anyone have an amazon link to a nice inexpensive IR device? What clear tape are you using that will hold up to the temp of the group head.

Thanks,

Ken

I picked up a couple at Harbor Freight but I actually use them for work, not for espresso, to measure the temperature of equipment and the ambient temps in communications shelters.

As for tape, you have a couple choices.

The easiest is masking tape (not clear but it comes in black or white and both have an emissivity of roughly .95, black can look cool depending on where you stick it). Masking tape tends to separate a little after a while, but it won't hurt the chrome, and if it leaves any residue it can be easily removed with goo gone.

You can also use a clear scotch tape. It holds up well to the heat and if you place it well is almost invisible to the casual observer. It will likely read on the low side, as its emissivity is .818, but if you can change the emissivity setting on your IR gun then it should do a good job of compensating for it.
Scotch tape is a bit harder to remove than masking tape, so be careful not to use anything that could scratch your chrome to remove it.

I am using a cheapie IR thermometer: Etekcity Lasergrip 774. Seems to be accurate enough for our purpose.

There's a deal on Amazon right now where if you use the promo code TEMG4OFF it will take off another $4.38x for a final price of $11.50 and free shipping if you have their Prime membership. Deals on Amazon usually expire quickly so act quick. Note: I found this deal on one of the popular deal sites but I didn't want to post a direct link.