horizontal geophone the output of which was 13 56 volts in sec velocity referring to fig3 b 4b and 5b bellows 14 was a standard bellows manufactured by metal bellows corporation of chatsworth calif the pumping system attached to conduit 17 constituted a leybold heraeus trivac model no s8a referring to fig5 b tube 20 constituted a 5 30 4 50 u00d7 6 in miniature rubber inner tube whereas hoop 27 constituted a metallic clamping ring having an inside diameter slightly less than the outside diameter of the normally inflated 30 psi tube the process station attached to conduit 18 was designed to require a mechanical stability of at least 0 003 in sec velocity 0 000016 in displacement and 0 0015 g 39 s 0 603 in sec 2 referring first to fig3 a and 3b it should be noted that the tested bellows arrangement included a rigid spacer or support 31 secured between flanges 15 16 as shown in fig3 a the peak frequency of 13 75 hz was accompanied by a 48 5 db amplitude referring to the experiment illustrated in fig4 a and 4b conducted on an unsupported bellows 14 a peak frequency of 7 5 hz was accompanied by a 30 6 db amplitude now referring to fig5 a and.