公开(公告)号：WO2018156137A1

公开(公告)日：2018-08-30

申请号：PCT/US2017/019183

申请日：2017-02-23

Applicant: JOHNSON CONTROLS TECHNOLOGY COMPANY

Inventor： SPORS, Daniel J. ,  HJORTLAND, Daniel R. ,  ERICKSON, Christine R. ,  KLARKOWSKI, Brian D.

IPC: G01K15/00 ,  G01D3/028 ,  G01K1/00 ,  G05D23/19

CPC classification number: G05D23/24 ,  G01K7/22 ,  G01K2201/00

Abstract: A method of monitoring the performance of a chiller system includes receiving a temperature sensor reading from a temperature sensor on an input channels at an analog-to-digital (A/D) converter interface. The temperature sensor reading is converted into a first value and then converted into an equivalent resistance value using a set of calibration parameters. A first set of configuration parameters are applied to the resistance value to compensate for inaccuracies in the conversion. The resistance value is adjusted based on an internal temperature parameter. A second set of configuration parameters is applied to the resistance value to account for sensor drift over time. A set of coefficient values related to the characteristics of the sensor are received and used to convert the adjusted resistance value into a temperature value. The resistance value and temperature value are transmitted to an external system for monitoring the chiller system.