This document mainly introduces a portable indicator, including DC ammeters, AC ammeters, pointer frequency meters, high frequency ammeters, power factor meters, power meters, small portable ammeters and voltmeters, as well as other auxiliary equipment. The document also emphasizes the limitations of use environment and conditions, as well as the precautions for connection and maintenance.

LH823 is a small power amplifier with a voltage gain of 1. It has the characteristics of wide bandwidth, large output swing and wide working temperature range. It can be connected to general linear and nonlinear components for power amplification, and used as voltage regulator, combination amplifier, and circuit terminal drive power amplifier. It is widely used in various automatic control, communication and exploration equipment. This product can work stably in 175℃ environment and can be interchanged with BeckMan 823.