If a tank's level is measured by a dipstick, this is considered-------

The measurement of a tank's level by a dipstick is considered direct because it involves taking a physical measurement using a tangible object that is inserted into the tank. When the dipstick is withdrawn, the level of the liquid on the dipstick provides a straightforward indication of the liquid level within the tank. This type of measurement is unambiguous as it directly reflects the actual level without the need for additional calculations or interpretations.

Direct measurement methods are often preferred for their simplicity and reliability, making them an essential part of many instrumentation processes in various industries. In this case, the dipstick provides an immediate visual reference, enabling the user to quickly assess the liquid level.