The PM2519 automatic multimeter is a digital multifunction measuring instrument with an internal microprocessor that results in a simple but extremely powerful measuring tool. The standard measuring functions of voltage, current and resistance are provided with auto-ranging and true r.m.s. a.c. measurements. Additional measuring functions include: - dB measurements with choice of 0 dB reference - frequency measurements - temperature measurements with a Pt 100 probe - relative reference measurements against a selected or set zero - continuity checks, and the measurement of the forward/backward resistance of diodes. Output values are indicated on a 41Λ - digit liquid-crystal display (LCD) with decimal points and a wide variety of function indications. A built-in bargraph gives an analog indication of outputs, enabling trends and orders of magnitude to be seen at a glance. An audible signal is available for continuity and level checks against a set relative reference value. The PM2519 is normally operated from an a.c. mains supply, but a /21-version is available for field operation that can be powered from internal batteries for a approx. 30 hours, these batteries are rechargeable in situ via the instrument's mains supply. A wide range of optional accessories are available, including temperature, EHT, HF and data hold probes, shunts and current transformers. 2.1. VERSIONS PM2519/01 The PM2919/01 is the basic version of the automatic multimeter. From this typenumber the following versions are derived. PM2519/21 A PM2519/01 with a built-in battery option. The rechargable batteries of the PM2519/21 can be charged via the instrument's mains supply. PM2519/51 The PM2519/51 version has a system adaptor and an IEC-625/IEEE-488 bus interface for digital output data and remote control (except for the main function switch).