Surface Temperature Thermometer

[Shel_B]

I've seen two types of thermometers used to measure the surface temps of pans, etc.  I'm curious about them. One style has a flat head on a probe, and the temperature is measured by contact. The others style I've seen is a temperature gun pointed at the surface you want to measure and can be used at a distance from that surface.

 

If you've used either of these styles, I'd like to hear your thoughts about them.  What are the pros and cons of each type?  Are they accurate and consistent?  Have they helped your cooking?  Any brands that you'd recommend?

 

I'm just starting to think about getting one having seen them used recently on several cooking shows.  

[Laurentius]

I have both types.  They each have their advantages.

 

Contact thermometers are generally more accurate.  But as the name suggests, they require not only contact with the pan, but good, dependable contact.  I have the Thermapen Contact, which I like, but the button head needs attention to keep it in full contact.  I also have Thermoworks commercial griddle thermometer, which is weighted, so it requires less attention.  There are also "wire" contact probes which can be super accurate; but they must be taped in place--not very practical for cooking.

 

IR gun thermometers CAN be accurate, but they measure only surfaces.  So if you have oil in a pan, oil is all they measure.  Another source of their inaccuracy lies in the fact that their readings depend on the emissivity and polish of the pan surface.  Good guns allow you to adjust emissivity to TRY to match the metal, but even with the same metal, a polished surface will read differently from a brushed surface.  IME, guns are gross measuring tools, better suited to comparisons than accuracy.  But they are CONVENIENT.  Another thing to remember is that guns read AVERAGE temps across an invisible spot that increases or decreased with how far you hold it from the food.

 

As for brands, I can't recommend Thermoworks enough.  They have a wide and deep selection that encompasses scientific, industrial and professional culinary uses.  They innovate, and their tech and customer service are first-rate.

 

You might be surprised to find it's not necessarily an either/or choice between contact and IR gun.  You should look at TW's IR gun handheld with a second channel to accept a Type K probe.

 

A base unit that takes the many kinds of Type K probes is a very good thing, and you can always keep a separate, inexpensive IR unit, too.

 

Hope this helps.

[JoNorvelleWalker]

I have four contact thermocouples, three from Thermoworks.  The surface contact Thermapen is convenient but has a limited temperature range.  My favorite surface probe rolls on wheels which helps to keep it stable on the surface.

 

The problem with IR surface thermometers is the readings depend on emissivity.  At the same temperature a cast iron skillet and a stainless skillet will read much differently.  Black cast iron has much higher emissivity.  Think of a cast iron Franklin stove.

 

Emissivity is also why smash burgers are cooked on stainless steel.  The meat cooks by conduction, not by radiation.  IR thermometers are measuring only radiation.

 

 

[gfweb]

6 hours ago, JoNorvelleWalker said:

 

.  At the same temperature a cast iron skillet and a stainless skillet will read much differently. 

 

 

 

 

 

 

How much differently?

 

 

[Shel_B]

Thanks for your comments.  Much appreciated.

 

Has using these thermometers improved your cooking in any way?

[rotuts]

adjustments can be made for emissivity :

 

https://www.calex.co.uk/find-correct-emissivity-setting-infrared-temperature-sensor/

 

Im not sure I completely agree w @JoNorvelleWalker statement 

 

'''' Emissivity is also why smash burgers are cooked on stainless steel.  The meat cooks by conduction, not by radiation '

 

stainless steel is used probably more for its durability and easy of cleaning , and lack of ' staining ' w acid foods

 

a cast iron surface will cook a terrific smash burger , and the meat doesn't have a preference on cooking energy.

 

I have a very small IR probe , but never got the Thermoworks more expensive model , that allows

 

for emissivity adjustments.    

 

for hope cooking , its a fun tool if you want to put the effort in emissivity adjustments

 

but I doubt using these values changes much ' on your plate '

[palo]

1 hour ago, rotuts said:

but I doubt using these values changes much ' on your plate '

Well said and should be applied to many culinary theorems that rely on science instead of taste

 

p

[liuzhou]

I have no doubt there are occasions where surface temperatures matter in culinary contexts but in 70+ years, I've never met one. I do have a gun type thermometer but rarely use it. The Thermopen gets almost all the work.

 

Maybe just my cooking but internal temp is what I'm interested in.

 

 

[JoNorvelleWalker]

6 hours ago, gfweb said:

 

 

How much differently?

 

 

 

I wouldn't know.  I don't have an IR thermometer.  Except for the Thermoworks Wand I got at the start of Covid.

 

As to cookware, from what I've read stainless steel has an emissivity coefficient of 0.07, whereas cast iron has an emissivity coefficient of 0.64.

 

[JoNorvelleWalker]

3 hours ago, rotuts said:

adjustments can be made for emissivity :

 

https://www.calex.co.uk/find-correct-emissivity-setting-infrared-temperature-sensor/

 

Im not sure I completely agree w @JoNorvelleWalker statement 

 

'''' Emissivity is also why smash burgers are cooked on stainless steel.  The meat cooks by conduction, not by radiation '

 

stainless steel is used probably more for its durability and easy of cleaning , and lack of ' staining ' w acid foods

 

a cast iron surface will cook a terrific smash burger , and the meat doesn't have a preference on cooking energy.

 

I have a very small IR probe , but never got the Thermoworks more expensive model , that allows

 

for emissivity adjustments.    

 

for hope cooking , its a fun tool if you want to put the effort in emissivity adjustments

 

but I doubt using these values changes much ' on your plate '

 

My information comes from Kenji:

 

"After just about 30 seconds, the burgers are ready to scrape. One of the great things about the Miraclean griddle is that it heats almost completely through conduction. That is, you have to come into direct contact with it to feel its heat—you can hold your hand inches away from its surface and not feel a thing. This means that while your crust is developing, the upper portions of the patty don't cook as fast as they would on a standard griddle."

 

[mgaretz]

I have an IR gun (actually two, because I thought one had been lost in the move - it turned up a day after the Amazon return period was up!).  I have never used it for cooking.  I mainly use it to make sure the grill and smoker temps are low enough to put the covers back on.  However, nine times out of ten I forget to put them on until the next day.  The good news is that they are pretty inexpensive.

[Laurentius]

5 hours ago, Shel_B said:

Thanks for your comments.  Much appreciated.

 

Has using these thermometers improved your cooking in any way?

Yes.  Contact and IR guns make preheating very predictable.  And they help a lot in assessing evenness of hobs and cookware.

 

However, the penetration and immersion (and to a lesser extent, air) probes make a greater impact on my cooking and knowledge.

[Laurentius]

2 hours ago, JoNorvelleWalker said:

 

My information comes from Kenji:

 

"After just about 30 seconds, the burgers are ready to scrape. One of the great things about the Miraclean griddle is that it heats almost completely through conduction. That is, you have to come into direct contact with it to feel its heat—you can hold your hand inches away from its surface and not feel a thing. This means that while your crust is developing, the upper portions of the patty don't cook as fast as they would on a standard griddle."

 

This doesn't make sense to me, especially concerning griddles and smash burgers.  I'm thinking there really is no cooking role played by radiant heat here.  It's practically all conduction, no matter what the griddle is made of.

[Laurentius]

4 hours ago, Laurentius said:

no cooking role played by radiant heat here.

 

For some unexplained reason,  Kenji took the bait that this griddle radiates less heat.  While this may be true (and may be an energy boon), the culinary effect on griddling food is clear as mud.

[Slim W]

Pizza.  An IR gun ( that can read high temperatures) greatly improved my end results. Was it reading an accurate floor temperature? No idea, but it allowed me to get a range that worked and was repeatable. 

My gas range is very unpredictable, I try and use the Control Freak for most tasks, but I only have one. So I can get my carbon steel or cast iron to range that has worked well on the CF. Other than pizza use case, I could do without it, but I like having it. 

[haresfur]

I use my IR thermometer now and then. Mainly when preheating a pan or now and then for shallow frying oil to know when to add food. It is decent for pseudo-Neapolitan pizza where you get a pan screaming hot and whack the pizza in to cook the base for a few minutes then finish under the broiler. I should use it more but usually wing it. Aside from that, it is ok at figuring out when the gas grill is heated enough and how even the heat is (for mine it is not). I did love seeing the science geek kid running around Old Faithful geyser basin at Yellowstone, measuring the different hot springs. They don't let you cook in them anymore, though.

 

I don't think mine adjusts for emissivity, but that's not a big deal if you are using it to get consistency using the same setup or just to get ballpark temperatures.

[JoNorvelleWalker]

I had to laugh.  By "coincidence" Amazon is now wanting me to evaluate and review an infrared thermometer.

 

[Shel_B]

Thanks to everyone who jumped in on this.  Considering your comments, I'll pass on a surface thermometer.  The oven thermometer and the Thermapen should be fine going forward. I do love the Thermapen, and use it a lot.

[Laurentius]

5 hours ago, Shel_B said:

Thanks to everyone who jumped in on this.  Considering your comments, I'll pass on a surface thermometer.  The oven thermometer and the Thermapen should be fine going forward. I do love the Thermapen, and use it a lot.

 

Save your $ for a Thermoworks RFX wireless probe kit.  https://www.thermoworks.com/rfx-starter-kit/  I don't have one yet, but it's claimed they are submersible in oil, and have predictive powers for finding the thermal center of foods.  Extremely long range, too.

[JoNorvelleWalker]

Now that Amazon has sent me an IR thermometer to test I did a quick experiment:

 

I measured a stainless steel pan and a cast iron pan both at room temperature.  At the default emissivity setting of the instrument the stainless steel measured 25C and the cast iron measured 26C.

 

[Laurentius]

1 hour ago, JoNorvelleWalker said:

Now that Amazon has sent me an IR thermometer to test I did a quick experiment:

 

I measured a stainless steel pan and a cast iron pan both at room temperature.  At the default emissivity setting of the instrument the stainless steel measured 25C and the cast iron measured 26C.

 

 

Now compare close-in, at oblique angles, and at the pan shoulder.  High polish should be wider.

 

You already know the temperature in the room.  Did the readings match?

[JoNorvelleWalker]

1 minute ago, Laurentius said:

 

Now compare close-in, at oblique angles, and at the pan shoulder.  High polish should be wider.

 

You already know the temperature in the room.  Did the readings match?

 

As I said, one was 25C and one was 26C.  Not much difference but cast iron measured higher than stainless, as predicted.