High-speed transient recorder

The non-storage oscilloscope can be found in most electronic test situations, from sophisticated research laboratories to production engineering plants. The storage unit is most widely used in medical work and in electromechanical applications, particularly where very high-speed transients need to be recorded, while, as noted above, the sampling type finds its main use in the evaluation of ultra-high-frequency equipment. 

Tests were carried out at 23°C on a pipe-grade (PEIOO), modified high density polyethylene, at speeds between 0.2 and 2 m/s. The impact speed was calculated from the initial drop-weight height and load/time traces were recorded using a Nicolet high-rate transient recorder system. 

The reactor described herein may be considered third generation. Data collection was first accomplished by recording the analog signals on a tape recorder. Later a modified PDP-15 dual processor digital computer was directly coupled to the reactor itself. The equipment was completed in 1971 (7). Since that time others including Becher CS), Wolfe (9), and Nash ( ) have used the system for high speed transient adsorption/reaction studies. 

Spectrum acquisition rates are a major concern in high-speed GC-MS where total separation times in seconds and peak widths typically less than 200 ms are common. The separation conditions are relatively easy to achieve with short, wide bore, open tubular columns operated at low pressures [131-136]. The ion source of the mass spectrometer provides the vacuum source for the column. Time-of-flight mass analyzers are most suitable for these applications. Time-of-flight mass spectrometers in production are capable of recording up to 500 full-mass spectra per second based on averaging 10 transient spectra per single spectrum [135-138]. At present, this is a unique... 

Real-time infrared spectroscopy (RTIR) (21). The basic principle of this analytical technique consists of exposing the sample simultaneously to the polymerizing UV beam and to the analyzing IR beam, and monitoring on a high speed recorder the sharp decrease of the acrylic absorbance at 812 cm l. Conversion versus time curves have thus been recorded for the first time for photopolymerizations that develop extensively in a fraction of a second (211. If the reaction time drops into the millisecond range, a transient memory recorder (221 or an oscilloscope with storage function can be used to shorter the time resolution further. 

The high frequency output signal is sampled by a digital transient recorder. In most experiments a sample rate of 0.2 ms. was used. In film thickness geometry studies a saifple rate of less than 10 ps is needed (at 5 s shaft speed). 

For the standby pump start test, which is an important test to ensure the pumps transfer without large pressure swings, a check should be made to see if the relief valves lift or the pressure falls to a pressure one half the difference between the standby pump start pressure and the compressor trip pressure. The transient pressure is best measured with a multipen chart recorder. The chart speed must be high enough to fully display the pressure variation. While not as good as the chart recorder, a simple shop-made test setup can be substituted. A spare switch is temporarily connected to the same location as the other switches. This switch is calibrated to close at the threshold acceptance pressure. The contacts are wired to a test light through a seal relay. The purpose of the relay is to maintain the cir-... 

Values of A , and k may be extracted from the polarographic data, although the treatment is complex. Examples of its use to measure the rate constants for certain redox reactions are given in Refs. 339 and 340 which should be consulted for full experimental details. The values obtained are in reasonable agreement with those from stopped-flow and other methods. The technique has still not been used much to collect rate constants for homogenous reactions. The availability of ultramicroelectrodes has enabled cyclic voltammograms to be recorded at speeds as high as 10 Vs". Transients with very short lifetimes (< ps) and their reaction rates may be characterised. ... 

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