Thermometer

[bdoss2006]

I bought a food thermometer on Amazon (Rubbermaid Commercial Products Food/Meat Instant Read Thermometer, Pocket Size, Dishwasher Safe, Red, For Meat/Food Cooking and Grilling/Oven https://a.co/d/hJB63jm) will it work for black and white developing or do I need an actual photographic thermometer?

 

[Brad Deputy]

It can, as long as you can ensure its accuracy.

For me the Ilford colour stick thermometer is my standard as I believe they're accurate to under 0.5F.

I also buy those meat thermometers, my favorite the ones they sell with a plug in style with a full display and alarm. I get them from Bed bath and beyond for $15-25 each. They're usually within 1F accuracy and they read in 2-3 seconds after inserting into chemicals.

I don't see a point in getting anything more pricey, even for color chemistry, unless you require extreme accuracy to the 10th of a degree.

 

[Nicholas Lindan]

Plenty good enough for B&W. You really only need to be within 2F - repeatability is more important than accuracy.

 

[blee1996]

For color processing, I use thermometer and sous vide, and eye on the clock every 30 seconds.

For black and white, I just use tap water and my eyes blindfolded.

 

[mshchem]

I use dial thermometers that I check against Kodak thermometers.

These little Jobo thermometers are fabulous, available used, new if you can find one.

 

[Craig]

I bought a spirit lab grade thermometer at a science supply place intended for schools. It was under $10 and accurate.

Similar to this one: https://www.fishersci.com/shop/products/fisherbrand-spirit-thermometers-student-grade-10/13201401

 

[MattKing]

I have an excellent reference thermometer - a Kodak Process thermometer in fact.
I use it to regularly check the thermometers I use on a day to day basis - an inexpensive modern digital display thermometer, and an old designed for darkroom rotary dial thermometer. The latter is used more for tracking wash water temperatures than anything else
Both of my day to day thermometers are designed for a narrower temperature range than the Betty Crocker thermometer linked to by the OP - that thermometer would be a bit difficult to use for photography, because it is hard to reliably track one ore two degree changes.

 

[Philippe-Georges]

I bought two digital thermometers in an electronic components supply shop (Velleman).
One for developers and water only and one for all the other liquids, so I need less-to-no water to clean them.

I still hold on to my Kodak process thermometer as a reference, which I used to calibrate the thermostat of the Colenta developing machine.

I normally used the traditional mercury in glass thermometers, but these got to easily broken...

 

[awty]

Get one that measures C's, F's make no sense.

 

[guangong]

I am still using my old glass mercury Kodak thermometer bought many decades ago. I surprise myself that I haven’t broken it in all these years. I have a couple dial thermometers which are handy for monitoring any temperature changes during processing.

 

[Neal]

It will be fine. Start making photos!

 

[L Gebhardt]

Get one that measures C's, F's make no sense.

Maybe if you didn't grow up using it. Since you're just trying to hit a target when developing using what ever you're comfortable with is fine.

 

[BAC1967]

I have an infrared thermometer that I had originally used for work several years ago. It's very good quality and has a large range, up to 2,000 F, not that I need it to go that high for developing. I like it because I can just point it and get a quick reading. Of course, need to be stirring the liquid so you're not just reading the surface temperature.

For work I used it on a mobile incinerator to check for problems, like failure in the fire brick. You could detect a failure in the fire brick before it burned through the steel wall by finding hot spots. It was also a good for checking if a bearing was going out, it would get hot before it seized up. We also had many thermocouples on the incinerator that we had check to make sure we were still getting accurate readings on our control instruments.

I think some of the cheap infrared ones they started selling for COVID are very inaccurate. I was using them to check the temperature of employees as they arrived for work each day. I got suspicious when everyone had exactly the same temperature. Those ones are complete garbage.

I do have a mercury thermometer but I'm nervous about breaking it. At least I can use it to compare with other thermometers.

 

[George Collier]

Consistency (precision) is more important than accuracy. My temperature control water valve is 2˚ off from my dial Weston process thermometer. I use the Weston for all chem measurements and set the water valve 2˚ high for the wash. I don't really care which one is correct, I just never vary from this, having long ago adapted all times and temps to this set up. Consider the range of recommendations for any film/developer in the Massive Development chart - techniques and development conditions are all over the place - just make it work for you (adjust your times and temps - and don't forget agitation schemes) and be consistent.

 

[chuckroast]

I bought a food thermometer on Amazon (Rubbermaid Commercial Products Food/Meat Instant Read Thermometer, Pocket Size, Dishwasher Safe, Red, For Meat/Food Cooking and Grilling/Oven https://a.co/d/hJB63jm) will it work for black and white developing or do I need an actual photographic thermometer?

Those are kind of ratty. I use this from Amazon:

Alpha Grillers Instant Read Meat Thermometer for Grill and Cooking​

And it's more than good enough. Just rinse off the probe every time and try to keep chemistry off the body of the thermometer. I usually rinse the probe after use, and wipe the body off with a slightly damp paper towel. I've checked it against a Kodak process thermometer and - at least for monochrome - these are plenty accurate.