Check the listing for details. Proof and Tralle Hydrometer in Hard Pack Case (0º - 200º Proof). Condition: New. Listed at 5.19 USD. A Proof and Tralle hydrometer directly measures the alcohol content of distilled alcohol or spirits. This hydrometer provides 2 scales of measurement which are Proof (the US International Revenue Scale for proof of spirits) and Tralle (the actual percentage of alcohol). It is calibrated to give accurate readings at 60ºF (15.6ºC) and includes a temperature adjustment chart. It includes a rigid, hard pack case for added safety. Measuring Range: Proof Scale: 0 - 200 (2º Resolution)Tralle Scale: 0 - 100% (1% Resolution)Calibration Temperature: 60ºF (15.6ºC) Dimensions: Length: 11in (28cm) Overall Width: 11/16in (18mm) Stem Width: 3/8in (9mm)Material: Hydrometer: Glass Internal Weight: MetalMore Info: A Proof and Tralle hydrometer can not be used to measure the alcohol content of beer, wine or other beverages and can only accurately measure the alcohol content of 'pure' distilled spirits. It will not provide accurate results when testing distilled spirits such as cordials and liqueurs that have other dissolved ingredients or sweeteners including flavored spirits.To use the hydrometer, simply fill a test jar with the liquid sample. The volume of the liquid must be large enough to completely suspend the hydrometer. Place the hydrometer in the liquid making sure that there are no air bubbles clinging to the hydrometer. The resulting alcohol content is the reading on the hydrometer scale that intersects the surface of the liquid. Includes plastic storage tube.