Question

What precaution needs to be taken while using a clinical thermometer?

• A. The thermometer should always be handled through its bulb while reading it.
• B. The thermometer should be kept in sunlight for at least 30 minutes before usage.
• C. The mercury should be kept in line of sight while reading the thermometer.
• D. The thermometer should be washed with hot water before usage.

Answer 1

The correct option is C The mercury should be kept in line of sight while reading the thermometer.

While taking a reading of the thermometer by not keeping the level of mercury along line of sight, parallax errors will occur as shown in the diagram below.


To avoid this error, it is always advised to record thermometer readings while keeping the mercury level along the line of sight.