During a 6 a.m. inspection today, a line cook’s probe fogged after a 200 ppm quat wipe and started reading 10°F high. What thin-tip, waterproof models meet Food Code accuracy (+/- 2°F) and hold up to ice-bath calibration and hourly line checks at 135°F/41°F?
I’ve had the best luck with the CDN DTQ450X — thin tip, IPX7, ±2°F — and we stopped fogging by doing a quick water rinse before the “200 ppm quat” wipe and lightly greasing the battery o‑ring with food‑grade silicone; it still hits 32°F in ice and tracks hourly 135°F/41°F checks without drift. Are you sanitizing the whole body or just the stem during rush? ThermoPop 2 held up too, just pricier.
For our 6 a.m. hits, the ThermoWorks RT600C (IP67, ±0.9°F) has survived ice-bath calibration and hourly 135°F/41°F checks without fogging: Executive Series® Thermometer - ThermoWorks. After the “200 ppm quat” wipe, we leave the sheath off and stand it tip-down for a minute so the buttons don’t trap moisture. If you want an even thinner tip, the Cooper-Atkins DFP450W meets ±2°F but is a touch slower — anyone had it last more than a year under daily sanitizing?
Comark PDT300’s been our workhorse — thin tip, waterproof, NSF, ±2°F, and it re-calibrates clean in an ice bath… To curb that “fog then +10°F” after a sanitizer wipe at 6 a.m., let the head cool 30 seconds and keep the lens seam down so liquid can’t pool; a silicone boot helps. @lmartin if you like the RT600C, this is a cheaper sealed-button alternative: https://www.comarkinstruments.net/product/pdt300/.
What finally stopped the fogging for us was slipping a 1-inch heat-shrink sleeve over the stem/body seam on a Cooper-Atkins DFP450W (IPX7, ±1.8°F) — “no fog, no +10” — and it still calibrates clean in an ice slush. Want the tubing size and heat setting we use?
We’ve had good results with the CDN DTQ450X (NSF, ±0.9°F, IPX7); it takes ice-bath calibration well and stays stable during hot- and cold-holding checks. A pinhead of food-grade silicone at the probe entry, piggybacking on @cgarci31’s “seal the seam” idea, stopped any moisture creep: https://cdnkitchen.com/product/dtq450x. Only caveat: skip the dish machine — rinse and air-dry.