The Three-phase Reference Standard Meter (TPRS) is a portable device. It is used for testing three-phase and single-phase energy meters, also known as the meter under test (MUT). The TPRS can be used with both static and electro-mechanical types of meters, and it measures voltage, current, energy, power factor, and more for the meter under test. It features a 7-inch inbuilt colour display with a touch interface and can be connected to a PC for data analysis. Additionally, it can store up to 25000 test results.