Leeds and Northrup Speedomax

Analytical Apparatus. In the cold-trap method, mercury is detected by the gas-phase absorption of elemental mercury at 2537 A using a Coleman Instruments mercury analyzer (MAS-50) equipped with a Leeds and Northrup Speedomax recorder (model XL60I). The mercury ana-... 

Recorder, with millivolt range(s) compatible with the AA spectrometer and with a similar 0.5-sec response time. A Jarrell-Ash model 82-500 AA spectrometer and a Leeds and Northrup Speedomax W 10 mV recorder were used in the development of this method. 

Motions of the torsion head are recorded in the following manner the shaft of the motor controlling the torsion head is attached to a small cylindrical potential divider ( Helipot ) in which a few milliamperes constantly flows. The voltage taken off the divider varies with the position of the torsion head, and is fed directly into one point of the Leeds and Northrup Speedomax two-point recorder. This then registers a measure of the specific magnetization of the sample. 

Pyrolysis gas chromatograms (PGC) were obtained on a model AIOOC Wilkens Aerograph gas chromatograph equipped with a Leeds and Northrup Speedomax G Recorder. The copper chromatography column was packed with acid washed chromosorb W and 20% SE-20. Pyrolysis was accomplished by placing a small, dry sample of polymer on a Rh-W, code 13-002, Gow-Mac coil and pyrolyzing for a predetermined time. 

Jacket temperature was controlled by connecting the thermoregulator and the heater to an American Instrument Co. relay model No. 4-5300. Power to the heater was supplied by a 60-cycle variable transformer normally operated at about 10 volts. Jacket temperature was recorded by feeding the thermocouple output through a Leeds and Northrup d.c. amplifier (No. 9835-B) to a Speedomax H Azar strip chart recorder. 

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