Multiple thermocouple testing device

摘要

An automated multiple thermocouple testing device determines short and open circuits in a thermocouple system. The thermocouple system has a plurality of temperature probes, each probe has a first thermocouple and a second thermocouple. The device applies a direct current voltage to the first thermocouple to cause heating in the second thermocouple and then reads the temperature response of the second thermocouple. The first thermocouples have a common lead and the second thermocouples are connected in two parallel groups. The temperature output of the second thermocouple is digitized and read by a computer. These readings are compared to criteria which determines if there is an open circuit. Before the open circuit test is applied, the device also determines which thermocouple probe has a possible short circuit. This device can automatically test for short and open circuits in a thermocouple system within a few minutes without the necessity of removing the probes from their installed position. This device was adapted to preform the above testing on a F100 fan turbine inlet temperature (FTIT) system.