This Model 118 Polymeter appears to be made by Fischer of Drebach, Germany.  It doesn't have the Fischer logo but the Fischer company has confirmed that it was made by Fischer.  The lower instrument is a hair hygrometer that shows the relative humidity and also the depression of the dew point in degrees C.  The upper instrument shows the air temperature in degrees C and the saturation vapor pressure in hPa (millibars).  The dew point temperature can be determined by subtracting the dewpoint depression from the air temperature.  

Both dials are approximately 3.75 inches in diameter.  This polymeter probably had a long useful life as it came from the ship breakers in India.  It still works well, it's very dry indoors here in Chicago in December.  I don't know the manufacturing date but it's probably in the 1980s. It has a newer dial design than the 1971 Fischer catalog.  Very similar polymeters continue to be sold in the current Fischer catalog, which may be found here.

Go to Fischer catalog page.

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