The heating elements are pulsed by an electrical circuit at a rate substantially faster than {TAIL ~ the rate} of {HEAD ~ introduction} of new assay cartridges 
The heating elements are pulsed by an electrical circuit at a rate substantially faster than { TAIL ~ the rate } of { HEAD ~ introduction } of new assay cartridges
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH