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Digital temperature thermometer

stevenje

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I need some advise / suggestions on buying a digital temperature thermometer with a wired probe. It would be used to monitor darkroom chemicals during the printing process. Thank you in advance.
 
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stevenje

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koraks said:
What kind of printing process and what kind of temperatures do you want to work at? Also, in what kind of container/vessel will the liquids be?
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Lith printing. 100º+/- . Tray with constant agitation.
 

koraks

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Thanks; I considered this might be the case, but wanted to check.

Frankly, for lith I wouldn't bother trying to control temperature and just go with the tried-and-tested method of pulling the print at the opportune 'snatch moment'. To get the temperature in the ballpark, I'd consider using a larger tray of hot water in which you place your development tray. The thermal mass of the water bath will dampen the temperature drift. Once in a while you can add some hot water to the larger tray. Or perhaps use some kind of thermostat to keep that bath at a more or less constant temperature.

Monitoring the actual developer temperature has little benefit in this case IMO.
 
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stevenje

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Thank you for the great information. I hope to try my hand at lith printing in the very near future.
 

RalphLambrecht

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stevenje said:
I need some advise / suggestions on buying a digital temperature thermometer with a wired probe. It would be used to monitor darkroom chemicals during the printing process. Thank you in advance.
Click to expand...

I bought the one from RHDesigns and it worksbut in general. I believe digital thermometers are not very accurate but very repeatable.
 

btaylor

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RalphLambrecht said:
I bought the one from RHDesigns and it worksbut in general. I believe digital thermometers are not very accurate but very repeatable.
Click to expand...

I’m sure that depends on the digital thermometer in question. A cheap way I have gone around this: I already have a Kodak Process Thermometer. I simply measured how far off the cheap digital probe thermometers were and marked the differential on the digitals. The repeatability was good. The readings were off +2 to -4 deg F at 100 def F, IIRC.
 

koraks

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stevenje said:
I hope to try my hand at lith printing in the very near future.
Click to expand...
Right, in that case, skip the thermometer for now and see how it goes before acquiring more equipment you may not need.
Btw, when I do lith (which is rare, but I did it fairly intensively for a short period of time), I just mix a faster developer that gets the job done in a few minutes at room temperature. With lith, there's a lot of control in the composition of the developer itself.
 

BrianShaw

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This is what I use for temp monitoring. Inexpensive enough to try and buy to form your own personal experience-based opinion. (If used for roasting meat, note that the USDA guideline settings will almost always result in dry, overcooked food.)

For spot checking temperatures , this can’t be beat. Traceable to standards and includes calibration certification. A bit more expensive but…

Thermapen Fast, Accurate Instant-read Thermometers

www.thermoworks.com
 
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wiltw

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There are meat thermometers with long wire probes, which transmit via radio signal to a separate receiver display, which would be suitable for monitoring that temperature has not drifted much off the starting temperature (even if they are not funmentally calibrated for accuracy)...it might initially show 98 when actual temp is 100, and all you need to see is the constant '98'. You can even use a sous vide for cookiing meat, to hold temperature of the water bath...mine holds within tenths of a degree variation.
 

btaylor

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Thanks for the link, Brian. I have wanted one of these for awhile, but was unwilling to spend over $100 for one.
I clicked on the link and they are running a sale- $40 off the instant read model so it’s only $75! So I bought one.
 
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M Carter

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For lith printing - in the US, search eBay for Salton Hotray - multiple sizes of tempered glass tray warmers with heat control. Shipping can be a little high since they're heavy, but the glass surface really makes for even heat. I have several in 11x14 sizes, one in 16x20, and I can put twodown for 20x24 trays. I have a wall-mount dimmer to control multiple trays. Warning - on full, they can be screaming hot, so a separate dimmer can be a good idea. A Harbor Freight Router Speed Control box is under twenty bucks if you don't want to wire up your own.

Thermometer - check Thermoworks. Their Thermopop is a screaming value in a digital, it's got no crazy bells and whistles, just fast and accurate. I also use their "Blue Dot" in the darkroom, it's a wired probe that can also bluetooth to your phone.
 
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