The base and case face are made of plastic. The case wall is made of iron or steel. A brass tube protrudes from the top of the case face. On the bottom of the case are two terminals. There is a brass knob in between the two terminals. On the case there is a 8.5 cm by 4.5 cm flat glass window. Underneath the window there is a small circular mirror with a black block underneath. Under the block are inscriptions “SENS. 0.01 uC/mm C.D.R.X. 270(Ohms) PERIOD 27.5sec RESIST 55(Ohms) CAT. NO. 2239E”.
Accession Number: 2009.ph.199
Primary Materials: Metal, Glass
Old inventory number = phy355. Under the block are inscriptions “CAT. NO. 2239E”. Underneath the glass window there is an inscription “LEEDS & NORTHRUP CO. PHILADELPHIA”.
Height = 6 cm, Length = 35.5 cm, Width = 16 cm
For making precision measurements of electric current.
Leeds & Northrup Co., Philadelphia, Pennsylvania, USA
Date of Manufacture:
Provenance: Collection of Dr. Martin Lee.
Additional Information and References: