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).
Technical data sheet for Rototherm dial indicating thermometers.
| Identifier | ExFiles\Box 156\1\ scan0050 | |
| Date | 20th December 1933 guessed | |
| ROTOTHERM THE DIAL INDICATING THERMOMETER WITH RANGES BETWEEN minus 150° F to plus 1000° F.{Mr Friese} These instruments are preferable in many ways to glass thermometers, for industrial uses, more particularly in that they are very easy to read and are extremely robust, as well as being very reasonable in price, the latter comparing very well with that of high class mercury instruments, and very much cheaper than normal dial indicating instruments. SYSTEM OF WORKING:- A multiple-helical-coil bi-metallic system is housed in the end of a rigid metal stem, necessitating only 2" immersion, and is directly connected mechanically to the indicator moving over a clearly graduated scale on a circular dial. CONSTRUCTIONAL SPECIFICATION:- This can be varied to suit customers specification, a range of instruments already supplied being illustrated on our Broadsheet. In nearly all these cases the dial can be of 2½", 4" or 6" diameter, and vertically or horizontally disposed to the stem, which in turn is of any length from 4" to 40". The dial case in all models is in brass and can be finished in black lacquer or metallic plate, while the stem may be in brass or steel, plated or plain, or in special cases in some non-corrosive metal such as Stainless Steel. IMPORTANT FEATURES READING: This is a matter of comparative ease, more especially if one of the larger dials is used. STRENGTH: The whole instrument, apart from the glass-breakage of which in no way affects the accuracy - is constructed in metal, there being no danger of damage from shock or blow. ACCURACY: A normal accuracy of 1% on the range is guaranteed on all these instruments which are unaffected by thermal overload. It should also be noted that greater accuracy can be given when required for special instruments. There are of course, no capillary or other corrections. RANGE: This is more comprehensive than for any other type of thermometer, being from minus 150° to plus 1000° F.{Mr Friese} COST: This compares very favourably with all other instruments on the market. Although ROTOTHERM Thermometers can be supplied to cover practically any range that may be required, the following are the standard dials already in use:- -20° to +140°F 60° to 220°F -30° to +60°C 0° to +300°F 140° to 300°F 0° to +160°C 0° to +212°F 150° to 500°F Other ranges already supplied:- 0° to 800°F 50° to 400°F 100° to 750°F 0° to 1000°F 0° to 400°C 400° to 500°C (It should be noted that in the majority of these the scale graduations are linear) SPECIAL FITTINGS:- To nearly all the models illustrated, together with any others that may be specified, a modified glass and bezel carrying electrical contacts, either single or maximum and minimum, can be fitted. These are exceptionally valuable in connection with bell or lighting alarm circuits, or in conjunction with a special relay for temperature control. | ||