Email Document Reference

Enter your email address below and the reference for this document will be sent to shortly from webmaster@ceesi.com.

Title: Use Of Glass Capillary For The Development Of Gas Flow Transfer Standard
Author: Chih-Cheng Feng, Win-Ti Lin, Cheng-Tsair Yang
Source: 2009 International Symposium on Fluid Flow Measurement
Year Published: 2009
Abstract: Critical flow Venturis (CFVs), or sonic nozzles, are widely used as gas flow transfer standards. However, their application in flow rate below 1 L/min is usually limited due to the manufacturing difficulties. Therefore, the Center for Measurement Standards (CMS) is developing a laminar flow element (LFE) type flow meter as a transfer standard. This LFE consists of a single straight glass capillary or multiple straight glass capillaries connected in parallel. Two gauges and one thermometer measured the inlet/outlet pressure and inlet temperature, respectively, and the differential pressure was restricted from 2 kPa to 100 kPa. The glass capillaries were manufactured by laser machining, resulting in consistent inner diameter and straight flow path. Characteristics of glass material also prevented the capillary from bending during installation. By means of regression, the turndown ratio of this LFE flow meter could be higher than 20 and the residual would be still within 0.11 %. The reproducibility within 0.04 % indicated that this LFE flow meter can be used as a transfer standard. Moreover, the feasibility of using a bundle of multiple LFEs to expand the flow capacity while maintaining the length of the LFEs so that the flow meter can remain compact was also demonstrated. CMS will develop a series of flow meters that cover flow rates ranging from 1 sccm to 1000 sccm.

In order to prevent spam and automated file downloads for documents within the Measurement Library, please follow the instructions below and then you will be able to email a reference to this article.