مقياس حرارة فيرست كول - زئبقي

After years of dial thermometers drifting out of calibration on me, this darkroom spirit thermometer holds its readings rock steady through an entire development session. The markings are crisp enough to read in amber safelight, and it's been spot-on against my reference thermometer since day one.

The spirit column responds quickly, so I can check the temp between agitation cycles without holding up the whole process. It reads accurately against my reference thermometer, and for the price it's a solid darkroom workhorse.

The clear markings on this thermometer make it easy to read the temperature even in dim darkroom light, and it's held up well after a few months of regular use. I've been getting consistent development results since I switched to it for my black and white film.