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  1. #11

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    No way a 23 buck thermometer is legitimately certified. Maybe some hokey marketing definition of the term, but don't expect anywhere near the
    accuracy of the real deal. Certified thermometers are readily available from actual scientific suppliers in the two to three hundred dollar range.
    The Kodak Process thermometer is analogous, but made for the mid-range temps typical of a darkroom, and with a nice suit of stainless armor
    to protect from breakage. Type 3 is the best. Sometimes they turn up used reasonably priced. Yes, the main point in any darkroom is simply
    consistency, but some processes need better temp control than others and warrant purchasing the real deal.

  2. #12
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    Quote Originally Posted by DREW WILEY View Post
    No way a 23 buck thermometer is legitimately certified. Maybe some hokey marketing definition of the term, but don't expect anywhere near the
    accuracy of the real deal. Certified thermometers are readily available from actual scientific suppliers in the two to three hundred dollar range.
    The Kodak Process thermometer is analogous, but made for the mid-range temps typical of a darkroom, and with a nice suit of stainless armor
    to protect from breakage. Type 3 is the best. Sometimes they turn up used reasonably priced. Yes, the main point in any darkroom is simply
    consistency, but some processes need better temp control than others and warrant purchasing the real deal.
    Paterson are a very old and reputable company, and this thermometer is designed to be suitable for all colour processing and certified to be accurate to +/- 0.14 degrees C. nobody is asking for a sledgehammer to crack a nut.
    Ben

  3. #13
    AgX
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    Quote Originally Posted by DREW WILEY View Post
    No way a 23 buck thermometer is legitimately certified. Maybe some hokey marketing definition of the term, but don't expect anywhere near the
    accuracy of the real deal. Certified thermometers are readily available from actual scientific suppliers in the two to three hundred dollar range.
    Meanwhile there is a worldwide metrological standard for clinical thermometers.
    Seemingly the cheapest way to gain high accuracy. Of course with the stated disadvantages of these meters.

  4. #14
    jcc
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    Quote Originally Posted by DREW WILEY View Post
    No way a 23 buck thermometer is legitimately certified. Maybe some hokey marketing definition of the term, but don't expect anywhere near the
    accuracy of the real deal. Certified thermometers are readily available from actual scientific suppliers in the two to three hundred dollar range.
    The Kodak Process thermometer is analogous, but made for the mid-range temps typical of a darkroom, and with a nice suit of stainless armor
    to protect from breakage. Type 3 is the best. Sometimes they turn up used reasonably priced. Yes, the main point in any darkroom is simply
    consistency, but some processes need better temp control than others and warrant purchasing the real deal.
    Certified to what standard? My lab (science, not photo) uses $30 thermocouples from National Instruments (a scientific supplier), sampled at 50k per second—they're accurate, precise, highly sensitive... and cheap! Spending hundreds of dollars for a thermometer is just throwing away money, IMHO, but my opinion doesn't really matter as long as it's not my money.

  5. #15

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    Try making a matched set of color separation negs with one of those cheapie thermometers. The real deal is worth every penny. Up until last yr
    when the bldg got leveled for some expensive condos, there was a scientific supplier about four blocks away that sold nothing but thermometers for decade, mostly glass, and mostly expensive. Not a small inventory either. Let's see.... with biotech firms and
    pharmaceutical firms on almost every block around here, and UCB right up the street, somebody musta had a reason to keep him in business...

  6. #16

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    Thanks to all posters for the informative suggestions. A lot of opinion seems leaning towards the Kodak process thermometer which has the interesting feature of being calibrated at specific temperatures of prime interest to darkroom work and not exceedingly expensive. A high-grade lab thermometer might be in the future as an additional reference, and I might try the Paterson Color thermometer too (what's to lose at that price). That Jobo tempering box is awfully interesting - I see them on the used market at not ridiculously high prices, so it might be in my future as well. In the meanwhile I'll arm myself with improved thermometers and use manually controlled heat baths and chase the right temperatures to get started. I'll post some examples soon I hope.

  7. #17
    mts
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    note that most quality dial thermometers can be calibrated to read properly in the temperature range you need to measure. I have a dial thermometer that I use for color processing; calibrated with my 50-year-old Kodak color thermometer. Usually there is a small nut that can be turned to adjust the dial unit's reading. I keep the glass thermometer stored safely and use the dial to measure solutions in the sink.
    By denying the facts, any paradox can be sustained--Galileo

  8. #18

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    Agreed with AgX and others that electronic or other medical ("fever") thermometers are very useful for calibrating a dial
    thermometer for use in 100 deg. F color processes like C41. If you put your dial thermometer and (one or more, I used
    3 to be sure) medical thermometers into an insulated water bath at close to 100 deg. F, let them sit for a while, and take
    the reading, you'll get the right temperature even from a peak reading instrument (because it's not changing much). You
    can then adjust and use the dial thermometer that day and not worry about it being off.

    For B/W I calibrate the dial device against a Paterson alcohol thermometer that is tested at 68 deg. F.

  9. #19

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    I use the Paterson Colour Thermometer with good results.

    I determine the corresponding temperature on a digital LCD thermometer with a wire probe (Extech TM20) and use the digital thermometer. Using a pot of water at the target temperature, 20C on the color thermometer is 20.7 on the digital and 39C (for color film developing) is 39.6C on the digital. Calibrate periodically.

  10. #20

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    Unless you're doing research and needing to communicate hard standards, the most important thing with any thermometer is repeatability, followed by ease of use and reading. I gave up on digital thermometers because of their relatively slow response, and am not aware of any
    dial thermometer I'd consider accurate enough for critical color use. Some process standards are much fussier than others. I just don't like second guessing, so am happy with my Type 3 Kodak process thermometer.

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