GB716474A - Compound integrating meter for measuring quantities of gas delivered - Google Patents

Abstract

716,474. Gas meters. BRITISH OXYGEN CO., Ltd. Oct. 9, 1953 [Nov. 21, 1952], No. 29467/52. Class 54 A compound integrating gas meter comprises high and low range flow tubes 10, 11, provided with orifice plates 12, 13 and separate indicating and integrating meters 19, 22, a tandem valve 32 to simultaneously close one tube and open the other, and electromagnetic means for operating the valve whenever the flow crosses from one range to the other. The pointers of both meters are provided with electrical contacts which cooperate with contacts at the maximum and minimum readings of the low range and high range meters respectively. The minimum contacts on the high range meter act through a relay to energize an electromagnet 33 and hence lift the valve 32 so that the gas flow passes through the low range tube only until it reaches the maximum value of the low range meter when the contacts thereon close to reverse the relay, de-energize the electromagnet 33 and hence permit the valve 32 to drop so that gas passes through the high range tube only. To prevent hunting, an overlap of about 2 per cent is provided between the two ranges, a zero contact on the low range meter arranged in series with the minimum contacts of the high range meter prevents both meters from energizing the relay simultaneously. The electromagnet is supplied by a rectifier from an A.C. source. In order to check that the set pressure at which the instrument is required to function has been maintained throughout its operation, a pressure gauge 41 is mounted on the high range meter 19.