Mason's hygrometer - a wall-mounted wet and dry thermometer for determining the relative humidity.

The mason' s hygrometer measures the wet and dry temperature over the range of -10 to +50°C.

The mason's hygrometer is supplied with a slide rule for calculating the relative humidity to be calculated over the range of 1 to 97% RH. The mason's hygrometer housing is manufactured from robust blue ABS plastic and incorporates an integral hook for wall-mounting.

The case dimensions are 40 x 80 x 310mm.