What type of measurement does a differential pressure transmitter primarily provide?

A differential pressure transmitter is designed to measure the difference in pressure between two points, which is fundamental in various applications. This type of measurement is particularly useful for flow rate calculation, as the flow rate of a fluid through a pipe can be determined by measuring the pressure drop across an orifice, venturi, or other flow restriction devices. By applying Bernoulli's principle and the continuity equation, the pressure difference can be correlated to a specific flow rate.

The other options do not accurately reflect the primary function of a differential pressure transmitter. While it can indirectly relate to level measurements in closed containers by measuring the pressure difference between the liquid at the bottom and the atmospheric pressure (thus leading to a calculation of level), its primary role is not solely dedicated to this function. Similarly, it is not used for temperature measurement or for determining concentration in mixtures. Therefore, the differential pressure transmitter's core capability centers on flow rate calculations based on the differences in pressure it measures.