The 66252 Auto Switch is a unique, field installable option for Guildline’s Resistance Measurement Systems. Allows the use of your 6625 system resistance standards for both measurement and source applications without having to disconnect and reconnect wires. This option allows operators new flexibility when using the 6625A Measurement System. For example, the Guildline Model 6634A Temperature Stabilized Resistance Standard, with up to 10 available Resistance Standards, is typically hard-wired on 10 channels of the 6664 Series Scanners. It is normally difficult or time consuming to remove all the cabling and wires if an operator simply wants to use the Resistance Standards as a source for items such as artifact calibrations, high accuracy DMM’s and other metrology calibrations.