APPARATUS FOR MEASURING THE TIME TAKEN FOR THE CONSUMPTION OF A QUANTITY OF LIQUID BY A CONSUMING DEVICE SUCH AS FUEL FED TO AN INTERNAL COMBUSTION ENGINE

摘要

1419893 Consumption indicator; photoelectric apparatus H LIST 19 April 1973 [19 April 1972] 19042/73 Heading G1A and G1W A device for measuring the fuel consumption of an engine comprises a balance beam 1 pivoted at 2, a fuel container 3, a counterweight 8 for counterbalancing the empty container, a counterweight 10 for counterbalancing the weight of fuel to be consumed in a test, and a pair of photo-electric beam position sensors. Each sensor comprises a phototransistor 24, 25 and an optic fibre strand 17, 18 the light beam of which is arranged to be interrupted by a screen 15, 16 mounted on the beam, the strands 17, 18 having an oval cross section in the region of the screens. At the start of a test, the beam is in the position shown in Fig. 2 against an upper stop 14. As the fuel is consumed, the beam 1 rotates clockwise to deposit counterweight 10 on stops 13. At the same time, screen 15 interrupts the beam of strand 17 and a time recorder is switched on. When a further weight of fuel equivalent to counterweight 10 has been consumed, the beam rotates further so that screen 16 interrupts the beam of strand 18, and the time recorder is switched off. The container 3 may be filled automatically under the control of the beam position sensors, filling commencing when the beam of strand 18 is interrupted by screen 16, and ending when the beam of strand 17 ceases to be interrupted by screen 15. Instead of the screens 15 and 16 being arranged to interrupt the light beams of strands 17, 18 as the beam 1 rotates, they may be arranged to cease to interrupt the light beams. As shown in Fig. 1 the electrical part of the device may be isolated by a screen 28. Each photo-transistor may be mounted in a temperature compensation circuit Fig. 3 (not shown) which includes a pair of further photo-transistors which are blackened and which are thermally coupled to the photo-transistor by a metal block. The output from the photo-transistor may be taken via a Darlington pair of transistors arranged as an emitter follower impedance converter (Fig. 3)