Leeds Northrup recorder

Figure 12.5. Leeds Northrup Recorder (from Leeds Northrop Catalogue No. 84, 1918).

The TPD unit was constructed at the Signal UOP Research Laboratory. It Includes a Carle 111 H gas chromatograph with Pd/Ag hydrogen separator, Leeds Northrup temperature programmer, Bascom-Turner 8000 series recorder with data processing and storage capabilities and a custom designed quartz reactor. 

RoU chart recorders are made by the Brown Instrument Co., Bristol Co., Charles Engelhard, Hoskins Manufacturing Co., S. H. Stupakoff, Taylor Instrument Cos., Thwing Instrument Cos., and Wilson-Maeulen Co. The potentiometer recorder of the Leeds Northrup Co., which has a roll chart, is described in a later section. 

Automatic Temperature Control.—Indicators or recorders fitted with means for closing electric contacts are made by the Bristol Co., Brown Instrument Co., and the Leeds Northrup Co. Automatic control requires the expenditure of... 

The Leeds Northrup Co. has developed a two-couple continuous curve recorder for automatically heating furnaces to definite temperatures. As applied in carburizing and tempering of steel one thermocouple is placed in the furnace chamber and the other in contact with the steel piece. The controller automatically maintains the furnace for instance at 1,000°C. until the steel has reached 900°C. and then it drops the furnace to 900 C. Such an arrangement for control can be applied to a great many processes. 

The IR spectra were recorded using Pye-Unicam spectrophotometer, model 3-300. The specific conductivity of catalyst systems was studied using Leed Northrup conductivity bridge and cell. 

A Jarrell-Ash Model 82-532 MV spectrophotometer equipped with a Perkin Elmer nebulization system and a Leeds-Northrup Type W calibrated AZAR Recorder was used for the molybdenum analysis. The 3133 primary molybdenum absorption wavelength coupled with an acetylene-nitrous oxide flame were the basic parameters of the instrument. The recorder was set for a 5-fold signal expansion along with the amplifier at 3/4 damped position. 

Another important application of an electromagnetic flowmeter is in the external sodium line from the model tank to the dump storage systems. A Leeds Northrup direct current amplifier, Model 9835-B, is used to amplify the flowmeter signal to drive a Brown 0 to 4-mv. recorder to any desired amplitude for a given flow rate. This technique is very convenient to maintain a flow rate of 1 to 2 gallons per minute for the cold trap operation which follows the sodium charging. 

Apparatus. A Wilkens Aerograph HyFi Model A-610-B with electron capture detector was used. Two standard accessories, a detector heater and voltage control. Model A-630, were also employed. The output of the chromatograph was recorded on a Leeds Northrup Speedo-... 

Differential pressure across the Venturi with high flow rate conditions was measured with a Statham 0 to 100-psi pressure transducer. This signal was recorded on a Leeds and Northrup recorder with an adjustable span. The adjustable... 

All samples were analyzed in an AllTech 1/8"I.D, 20 foot column, packed with VZ-7 resin, using helium as the carrier gas. This column proved more effective for the measurement of the C4 components than the Poropak- N column. Ammonia was not detected by this column and as a result some of the assumptions employed to treat the solvent phase are described in a later paragraph. The G.C. was run with the injector chamber set at 115 C, the column oven temperature at 60 C and the filament current set at 150 ma. Column analyses were performed by an Autolab Integrator. A Leeds and Northrup strip chart recorder was used to plot the output of the integrator and to... 

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. 

Gas Chromatograph. Two Wilkens Aerograph Hy-FI chromatographs equipped with electron capture detectors were used interchangeably with a Leeds and Northrup model H recorder. The recorder had a 0-1-mv. span and a W per minute chart speed. 

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. 

One of the first precise vacuum or inert-atmosphere instruments was designed and constructed by Whitehead and Breger (37). The furnace was constructed from an alundum core, 9 in. in length by 2 in. ID, wound with Chromel A resistance wire. The core was shielded by four sheet-nickel cylinders, mounted on three posts, and the entire assembly was placed inside a 12 x 24-in. Pyrex bell jar. All electrical connections were made through the bottom of the bell jar mounting base. The sample block was made in the dimensions shown from Type 446 or 309 stainless steel. The furnace heating rate was controlled by a Leeds and Northrup Micromax controller the differential temperatures were recorded on a Beckman Photocell recorder. 

With the controlled atmosphere heated sample holder, it was a simple matter to connect a thermistor-type thermal conductivity cell to the system and, by means of an external multichannel recorder, record the DRS and the evolved gas detection lEGD) curves simultaneously (17). This modification of the apparatus is shown in Figure 9.4. The cell was connected to a Carle Model 1000 Micro-Detector system by means of metal and rubber tubing. The thermal conductivity cell was enclosed by an aluminum block which was heated to 100 C bv means of a cartridge heater. The block was connected to a preheat chamber, also operated at 100 C, which was used to preheat the helium gas stream before it entered the detector. The output from the detector bridge was led into one channel of a four-channel 0-5 mV Leeds and Northrup multipoint strip-chart potentiometric recorder. The temperature programmer from a Deltatherm III DTA instrument was used to control the temperature rise of the DRS cell. Output from the Beckman Model DK-2A... 

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. 

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