DE1573985

1,147,651. e Recording-apparatus. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Dec.22, 1965 [Jan. 7, 1965], No.755/65. Heading GlJ. [Also in Division H1] In a high resolution mass spectrometer installation, an electrical output is developed, indicative of the rate at which ions in a particular range of mass/charge ratios are received, which is recorded on a magnetic tape or drum. The output from the spectrometer is recorded on a magnetic tape 33 Fig. 1, by a multiple recording head 45, either in analogue form by amplitude or frequency modulation of a carrier signal or in digital form by using a conversion system to convert the analogue signals from the multiplier 17 to digital signals. In order to allow for variations in the speed of feed of the tape, the output from a stable sinewave oscillator 49 is also recorded on the tape to serve as a time marker. The tape can also be provided with a time marker indicating the actual time of scan, so that it can later be edited to eliminate blank parts of the tape between peaks. Alternatively, if the scanning time is long, the device may be used which starts and stops the feed of the tape so that it only records when the output from the spectrometer is sufficiently high. This has a limited use because peaks of intensity below the threshold of the device are not recorded. The tape can then be used in conjunction with a standard chart type recorder, a galvanometer recorder using an ultraviolet beam, an oscilloscope display system or a digital or analogue computer, suitably programmed (a suitable program is outlined in the Specification) to analyse the recorded output from the spectrometer.