Title: Thermometers
Course: Immunization - Ethiopia (Full)

Thermometers

Figure 6.11  (a) Dial thermometer, and (b) stem thermometer. (Source: WHO, 2004, as in Figure 6.1, p.13)

A thermometer is an instrument for monitoring the temperature of your cold chain equipment — refrigerator, cold box or vaccine carrier. It enables you to adjust the temperature to the correct range for the storage and transport of vaccines.

At a Health Post, either a dial or a stem (bulb) thermometer may be used to monitor the equipment temperature. On a dial thermometer, the needle moves around the scale, pointing to plus (+) numbers when it is warmer, and to minus (–) numbers when it is colder (Figure 6.11a). On a stem (or bulb) thermometer, coloured fluid in the bulb moves up the scale as it becomes warmer, and down the scale as it becomes colder (Figure 6.11b).

What temperature is showing on the thermometers in Figure 6.9? Is this a safe temperature for the storage of liquid vaccines?

Show answer

Both thermometers are recording a temperature of +5^oC. This is safe for storing liquid vaccines, which should be maintained between +2^oC and +8^oC.