Introduction

Mercury thermometers have long been used to measure temperature due to their accuracy and reliability. But, over time, they can become less responsive or fail to work as they should. The good news is that there are several ways to repair a mercury thermometer if it stops functioning correctly. In this article, we will explore four methods to help you get your mercury thermometer back in working order.

1. Resetting a Mercury Column

One of the most common issues with mercury thermometers is the separation of the mercury column from the bulb. This can occur if the thermometer was shaken or dropped. Resetting the mercury will reunite the separated mercury blob.

Steps to follow:

a) Hold the thermometer with the bulb end pointing upwards.

b) Swing it downward firmly and quickly, stopping abruptly when it reaches a perpendicular position.

c) Repeat this process a few times if necessary until the mercury column rejoins.

2. Cleaning and Polishing

Over time, tarnish on the outer surface or residue on the inner surface can cause fluctuations in temperature readings. By cleaning and polishing your thermometer, you can effectively restore its functionality.

Steps to follow:

a) For an external clean, use a microfiber cloth dampened with rubbing alcohol and gently wipe down the thermometer.

b) To clean inside, remove any residues using a syringe filled with rubbing alcohol.

c) Polish and buff the external surface of your thermometer using an appropriate metal polish.

3. Replacing a Broken Capillary Tube

If your thermometer’s capillary tube has cracked or broken, you’ll need to replace it before it can be used again.

Steps to follow:

a) Seek professional assistance from an experienced technician or purchase a replacement tube online or from specialist stores.

b) Carefully remove any fragments of broken glass from the old tube.

c) Insert and secure the new capillary tube, ensuring the mercury column is fully visible and not obstructed by any dirt or debris.

4. Calibrating Your Mercury Thermometer

Your thermometer may need recalibration if it consistently shows inaccurate temperature readings. To ensure your thermometer continues to provide accurate readings after a repair, you should calibrate it.

Steps to follow:

a) Immerse the bulb of your repaired thermometer into an ice-water slush (with a 50:50 ratio of ice and water) and wait for the temperature to stabilize.

b) Compare the reading to a known accurately calibrated thermometer also immersed in the slush.

c) If the difference is significant, consult a professional or technician to perform the calibration.

Conclusion

Mercury thermometers are sensitive instruments that require proper care and maintenance. By following these four repair methods, you can ensure your mercury thermometer remains accurate and reliable for all of your temperature-measuring needs. Remember, always handle your thermometer with care to avoid breakage or damage.