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).
Comparison of a standard Exide syringe hydrometer with a new type Exide syringe hydrometer, detailing good and bad points.
| Identifier | ExFiles\Box 44\5\ Scan076 | |
| Date | 16th May 1924 | |
| COPY EFC. 16.5.24. JB.45. X.3741. COMPARISON OF SYRINGE HYDROMETERS. Two syringe hydrometers, one a standard Exide and the other a new type Exide, were compared with each other in various strengths of acid, both hydrometers were found to be correct on all readings. Good points of new type Exide. (1) The top of the barrel is parallel, into which a rubber stopper is fixed. This stopper has three holes passing through it which allow the air to pass into and out of the bulb. This also prevents the possibility of the float coming into contact with the top of the glass barrel and breaking the float. (2) The float is improved by having small projections fitted which prevent it sticking. (3) The bottom of the barrel is widened out to admit the nozzle which is made in one piece of moulded rubber, the stem is also of rubber. (4) The upper half of the barrel is widened out to prevent the float sticking. Bad points. (1) In the two places where the barrel is drawn out there is a noticeable sign of weakness and liability to crack. (2) The barrel is rather too narrow to give the float a little clearance which is necessary, as it jams tight when about one inch off the bottom. It must be noted that the same type of float is used in both hydrometers. A report giving the good and bad points of the standard Exide is given in our JB.16 of 18.8.23. EFG/G.Johnson. | ||