A HALF-BRIDGE TYPE STRAIN GAGE FOR USE AT ELEVATED TEMPERATURES
Abstract
Development of the Half-Bridge strain gage is continued. Gage manufacturing and testing techniques were standardized. A theoretical analysis of gage performance is included. The following tests were made: (1) response of gages to rapid radiant heating; (2) measurement of gage factor at room temperature and as a function of temperature; (3) response of gages to slow (oven) heating; (4) gage drift at constant temperature. It is shown that: (1) gage performance depends strongly on bridge voltage; (2) the gage material selected on the basis of previous tests (Nichrome) is not fully acceptable for gage use, even in the Half-Bridge configuration, because of a metallurgical transition occurring above 1000 F; (3) the poorest Nichrome Half-Bridge strain gages tested exhibited a temperature coefficient of less than 3 microohms/ohm/F to 1000 F, more than an order of magnitude better than currently available uncompensated high temperature gages; (4) gage use above 1500 F is not generally feasible because of a lack of adequate cements and bonding techniques at these temperatures.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1964
- Accession Number
- AD0453872