Fundamentals of orifice meter chart recorders
- SEWCO Sales & Service, Amarillo, TX (United States)
The differential pressure chart recorder used to measure fluid flow through an orifice plate has gone through several design changes since it`s inception some sixty years ago. The present unit on the market uses two fluid filled bellows units connected together. One bellows senses the upstream pressure before the orifice plate, and the other bellows senses the downstream pressure after the orifice plate. This pressure differential created by fluid flow through the orifice plate moves the connected bellows on the back of the chart recorder, which are mechanically linked, by a rotating torque tube through the rear of the case, to the internal case linkage that is connected to an inking pen scribing a line on a circular chart. The ink line on a linear calibrated chart is proportional to the square of the now rate. While the significant information on proper recorder installation will be covered in the classroom. Due to space limitations, this paper will concentrate on a recommended method to precisely calibrate the chart recorder for maximum accuracy of measurement. The basic calibration procedure for the different pressure chart recorder (i.e. set zero, full scale and mid scale) has been taught for years. This paper does not intend to rehash old procedures that are fairly universally known. What this paper does present is a method to achieve a more accurate, more precise calibration than is prescribed in any manufacturer`s literature - and, at the same time, explain why this procedure is more accurate. In addition to being more accurate, this procedure has been proven to be faster than the compromise methods most recorder manufacturers advocate.
- OSTI ID:
- 146353
- Report Number(s):
- CONF-950553-; TRN: 95:007831-0115
- Resource Relation:
- Conference: International school of hydrocarbon measurement, Oklahoma City, OK (United States), 16-18 May 1995; Other Information: PBD: 1995; Related Information: Is Part Of Proceedings of the seventieth International School of Hydrocarbon Measurement; PB: 811 p.
- Country of Publication:
- United States
- Language:
- English
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