Pneumatic level switches are available for measuring which of the following parameters?

Pneumatic level switches are specifically designed to measure the level of fluids, typically using changes in pressure that correspond to fluid levels. They operate by detecting the pressure exerted by the fluid column above them. As the level of the fluid changes, it alters the pressure, which the switch can then interpret and signal accordingly.

While voltage and temperature measurement instruments exist, they are not functions of pneumatic level switches. These devices are geared towards pressure-related measurements, which clearly aligns with their operation principle. Therefore, the focus of pneumatic level switches as pressure-measuring instruments makes that choice the correct one.