From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Illustrated guide on the principle and operation of the METRETA liquid level measuring system.
| Identifier | ExFiles\Box 61\3\ scan0273 | |
| Date | 30th October 1931 guessed | |
| The Principle of the METRETA System of Measuring Liquid Levels Method of Operating the METRETA, after fitting: METRETA GAUGE (Fig. I): Dial Markings: PETROL, OIL, METRETA LEVEL GAUGE, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, OIL LEVEL INDICATOR, ROTHERHAM. MADE BY COVENTRY, ROBT. W. PAUL'S PATENT No239818/24, INCHES OF PETROL. Instruction Plate: BEFORE READING GIVE ONE TURN LEAVING HANDLE DOWN FIG. I. METRETA "B" (Actual Size). The most accurate method of measuring the depth of liquids in remote or inaccessible containers is that of forcing air through a pipe dipping into the bottom of the liquid: pressure of air required to balance the head of liquid above the outlet of this pipe is a measure of the depth. The METRETA employs no pump (a source of trouble in other gauges of this nature). By one turn of a small handle the user gets, automatically, a steady reading of the depth in inches, or the contents in gallons, of a tank which may be in any relative position. The readings thus obtained are exact and unaffected by the length of the pipe or by vibrations. FIG. II. FIG. III. METRETA "B" See that tap, if any, at top of instrument is open to either oil or petrol supply. The handle at the bottom pointing downwards, give it one turn in the clockwise or right-hand direction. The hand on the dial will then fall back to the correct reading of the depth of liquid. Subsequent readings can be taken at any time in the same manner. | ||