One thermometer bulb is kept constantly wet by a siphon reservoir while the other gives a dry temperature reading. Humidity is obtained by comparing the two readings on the enclosed chart. Uses a safe and easy to read red liquid in place of the usual mercury. Dual scales of -10/50°C and 10/120°F. Dim: 12″ x 27/8″ x 11/4″ (304 x 73 x 32mm). Weight: 4oz (108g).
| Thomas No | Mfr No | Description |
|---|---|---|
| 1226Z71 | 736740 | Hygrometer Masons |
