Philips Super Rotalix M

Ref. K6

This glass-metal tube, known as the SRM (the M standing for metal) is a double focus, large and small, and, as one can read from the label, can be run up to 150 kV. No other specifications are available. It dates from the late eighties

The metal part of the tube is most probably made of “kovar” an alloy of iron, nickel and cobalt, designed to have substantially the same “Thermal expansion” characteristics as “Borosilicate glass” in order to allow a tight mechanical joint between the two materials over a range of temperatures.

The X-ray window of the tube is made of beryllium.