250 mm slide rule for chemical engineers
(Click on the small pictures to see full-size images.)
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| (full-size
image: 477 kB) The front of this slide rule has a conventional set of scales: L K A DF [CF CIF CI C] D LL3 LL2 LL1 |
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| (full-size
image: 450 kB) This side has the special scales for chemical engineering. Most of these scales are identical to those on the Flying Fish 1017 rule. |
| Scales | Purpose of Scale | |
| Ch | two scales for setting atomic (and a few molecular) weights | |
| M1 | Xw | density unit conversion |
| M2 | X | density unit conversion |
| °F | Fahrenheit temperature scale | |
| °C | Celsius temperature scale | |
| °K | absolute (Kelvin) temperature scale, also usable as a C scale | |
| LM a/b | lm(a:b) | |
| mmHg | atm | pressure scale |
| Kg/cm2 | pressure scale | |
| in. Hg Vac. | lb/in2 gage | pressure scale |
| tw | vapour pressure of water | |
The °K scale has the following gauge marks.
| R1 | 1.986 | cal deg-1 mole-1 | molecular gas constant |
| R2 | 62.36 | litre mmHg deg-1 mole-1 | molecular gas constant |
| R3 | 0.08205 | litre atm deg-1 mole-1 | molecular gas constant |
| V0 | 22.414 | litre mole-1 | standard molecular volume of an ideal gas |
| F | 26.8 | amp hr g-equiv-1 | Faraday constant |
| k | 0.3594 | °K mmHg-1 | volume correction factor of an ideal gas |
| J | 4.185 | joule cal-1 | work equivalent of heat |
The complete instruction manual for the very similar Hemmi 257 slide rule can be found on the Sphere Research Slide Rule Site by clicking here.
This page was last updated on 8 June 2000.