Vintage Taylor Hygrometer Model 1331 Sling Psychrometer Type Measures Humidity.

Listed as “used” because even though it is in the original box with paperwork I cannot guarantee it has not been used. Plastic sleeve is discolored due to age. I am not sure when this was made but I believe it was between 1968 when Taylor Instruments merged with Ritter Pfaudler Corp forming the “Sybron Corporation” and 1974 when barcodes were placed on products due to the lack of a barcode on the box.