Kyushu Space Solutions Beckman Thermometer Use

Here are two common methods for calibrating a Beckmann thermometer within the temperature range typically used in experiments: **First, the Constant Temperature Bath Method** 1. Determine the temperature range you will be measuring. For example, if you're measuring the freezing point depression of an aqueous solution, the expected reading might be between 1°C and -5°C. If you're measuring boiling point elevation, the range could be between 99°C and 105°C. For heat of combustion measurements, the mercury column is usually best set around 2–3°C at room temperature. 2. Based on the intended range, estimate the temperature at which the mercury column should rise to the end of the capillary. In a standard Beckmann thermometer, the mercury rises about 2°C from the highest point on the scale to the tip of the capillary. Adjust the amount of mercury in the bulb accordingly. For instance, if you want the maximum reading to be 1°C during a freezing point experiment, the capillary’s end should be calibrated to read 3°C. 3. Place the thermometer in a constant temperature bath set to a temperature slightly above the desired calibration point—such as 5°C or higher—to allow the mercury to expand properly. 4. Remove the thermometer and hold it vertically with your right hand. Gently tap the upper arm with your left hand, as shown in Figure 3-3. This action helps break the mercury column at the elbow. Once removed from the bath, the mercury volume will change quickly due to the temperature difference, so this step must be done swiftly but carefully to avoid mistakes. 5. Place the adjusted thermometer into a constant temperature bath at the estimated working temperature. Observe the reading and check whether it falls within the desired range. For example, in Experiment 2, you can test the freezing point by using an ice-water bath at 0°C. If the reading falls between 3°C and 5°C, the calibration is appropriate. If not, repeat the adjustment steps. **Second, the Ruler Reading Method** This method is suitable for experienced users who prefer not to use a constant temperature bath. Instead, they rely directly on the temperature scale located on the upper part of the Beckmann thermometer. 1. Estimate the maximum operating temperature based on your experiment. 2. Invert the thermometer so that the mercury in the bulb and capillary slowly flows back into the storage bulb. Then tilt the thermometer gradually to connect the mercury in the reservoir. 3. If the estimated temperature is higher than room temperature, use warm water or let gravity assist the mercury flow into the storage bulb. When the mercury reaches the desired temperature on the scale, gently tap the thermometer as shown in Figure 3-3 to break the column at the elbow. If the temperature is lower than room temperature, submerge the thermometer in a lower-temperature bath until the mercury level matches the desired reading, then tap to disconnect the column. 4. Verify that the mercury adjustment is correct by repeating the process if necessary. **Precautions** First, the Beckmann thermometer is made of thin glass and is longer than a regular mercury thermometer, making it more fragile. Always store it in a protective case, mount it on an instrument rack, or hold it carefully. Never leave it lying around. Second, when adjusting, avoid exposing it to extreme temperatures or physical shocks. Third, be cautious not to accidentally connect the mercury in the capillary to the mercury in the storage tank, as this can affect accuracy. By following these steps and precautions, you can ensure accurate and safe calibration of the Beckmann thermometer for various experimental applications.

Sofa Sets

Sofa Sets,sofa set for living room,recliner sofa set,leather sofa set

Guangzhou LoPhiDa Co.Ltd , https://www.gzwidinlsa.com