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Session:

8B - Humidity 

Date & Time:

Wednesday August 9, 2:30 PM - 4:00 PM

Paper Title:

Temperature and Relative Humidity Calibration System 

 

 

Speaker:

Rick Walker, Senior Development Engineer  

CoAuthors:

Alan Cordner 

Speaker Info

Company:

Hart Scientific

Department:

Engineering

Address:

799 E. Utah Valley Drive
American Fork, UT, 84003, United States

Phone:

801-763-1600

Fax:

801-763-1010

Email:

rick.walker@hartscientific.com 

 

 

Abstract:

The need arose for a temperature and relative humidity calibration system that is capable of simultaneously calibrating a number of high accuracy temperature and relative humidity sensors. These sensors have temperature accuracy specifications as low as ±0.125°C over the temperature range 16 to 24°C, and ±0.25°C over the range 15 to 35°C. The relative humidity accuracy specifications for these sensors are as low as ±1.5% over the range 20 to 70%, 16 to 24°C and ±2.0% from 20 to 70%, 15 to 35°C. It is important to maintain a test uncertainty ratio between the specifications and uncertainties of the calibration standards of at least 4:1 and a TUR between the specifications and combined calibration uncertainties of at least 3:1. For efficiency, the system is required to be able to calibrate ten sensors simultaneously. Complicating the efforts to develop a satisfactory calibration system were the self heating and mutual heating of the sensors and temperature gradients within the calibration chamber. The system also needed to be convenient and operator-friendly. The authors and their colleagues set about to create a temperature and relative humidity calibration system that would meet the requirements. This paper further describes the relevant characteristics of the sensors of interest and the requirements of the calibration system. The construction and components of the realized apparatus are discussed. The performance of the system is presented in terms of calibration uncertainties, with contributing components detailed. 

 

 

 

 

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