• Stephen Biss

Upper Bulb Mercury Separation

Tip 12: During shipping of a new #duisimulator NIST mercury thermometer, the mercury column may separate leaving mercury in the upper bulb, shown in the image. Until repaired the thermometer is not accurate or reliable. The separation is repairable by gently heating the thermometer with warm water (slightly above 34 C), taking care not to explode the thermometer and spill mercury and glass. The Canadian distributor and the manufacturer provide instructions with the thermometer on how to safely accomplish this task. Defence lawyers should obtain disclosure, FOI, and O'Connor of all officer notes related to repairs of the mercury column, including NIST mercury thermometers very recently acquired.

When I purchased this thermometer new, it would not read any temperature. Upon close inspection I found a huge blob of mercury filling the upper bulb. I carefully followed the instructions and heated the thermometer until the lower mercury connected with the upper mercury. When the thermometer cooled all of the mercury seemed to shrink back into the lower reservoir. As best I can tell no mercury remains in the upper bulb. Can you tell from this image? The thermometer appears to work properly - it now reads 34.0 in my Guth 2100 simulator. But then I am using an unknown (the simulator digital display) to measure an unknown (my new NIST thermometer that I have repaired). I need to check its calibration(again even though it is new) against a more accurate and precise traceable reference thermometer.

#mercuryseparation #upperbulb #nistthermometer #tip

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