What type of measurement does a sight glass provide?

A sight glass provides direct level measurement because it allows operators to visually see the liquid level within a tank or vessel. This type of measurement relies on the principle of transparency, where the liquid within the sight glass is visible, enabling an immediate and continuous assessment of the liquid height.

This direct observation eliminates the need for calculations or secondary indicators, making it straightforward for operators in monitoring processes. It is particularly valuable in applications where quick visual confirmation of a level is necessary without the concern of calibration errors associated with indirect measurement techniques.

In contrast, indirect level measurements might rely on sensors, floats, or other devices that infer the liquid level based on different parameters, and temperature and pressure measurements do not provide information about liquid levels directly.