Chapter 2. Introduction
Güralp DM24 and CD24 digitisers, EAMs, DCMs and GPS receivers use 3 V lithium cells to power the on-board clocks and some non-volatile memory.
The installed life of a lithium cell is typically around seven years, whether the system containing it is in use or not.
The purpose of this document is to detail the procedures for replacing these cells.
2.1 Tools and Equipment
No specialist tools are required, although a scrupulously clean working environment is essential if an instrument is to be opened. The procedures in this document can all be carried out with the following commercially available tools:
The basic tool and equipment list is:
Hex keys ranging in size from 1.5mm to 2.5mm
Medium-sized, flat bladed screwdriver
Anti-static wristband
Non-conductive dowel or spatula for removing old cells
Aluminium foil for covering opened instruments.
2.2 Anti-static precautions
Caution: Circuit boards include components which can be damaged by electrostatic discharge. Always work on a properly grounded dissipative surface and wear a suitable grounded wristband. Ground yourself by touching an earthed conductor before handling any of the circuit boards.