Heise gauge

The experimental system used in this study is shown in Figure 1. The trickle-bed reactor was made up of 1.27-cm (Vi-in) OD, Type 316 stainless steel tubing with 0.32-cm (Vi-in.) OD, centrally located thermowell tubing. The reactor was packed with 8/10 mesh catalyst particles. The nominal reactor temperature was measured by a thermocouple which could traverse axially along the thermowell from the top to the bottom of the catalyst bed. The nominal reactor pressure was measured by a Heise gauge which was located upstream from the reactor. 

The piston-cylinder high pressure press used here is similar to those of previous investigators except for one major difference in the cylinder diameter (1 in. in this work J in. in others). The gauge pressure was read with a 16 in. diameter Heise gauge and multiplied by a factor of 100 to obtain... 

We measured flow rate with a Varlan P/N 29-000086-00 Soap Bubble Meter. The pressure gauges were Heise bourdon-tube type with 0.1 psla divisions. The column was 16 feet of 1/4 inch copper tubing packed with Carbowax 20M loaded to 20% on Fluoropak 90. 

The temperature was indicated and controlled to 0.1°C with a platinum resistance probe which extended 1 mm inside the inner surface of the cell. The pressure was adjusted using a 100 cc Ruska syringe pump and was measured to within 0.1% with a 710A Heise digital pressure gauge which is traceable to an NBS standard. The pressure varied less than 0.15 bar (2 psi) during a spectral scan. The wavelength accuracy was 0.2 nm for the Varian (Cary) 2290 spectrophotometer. 

The pressure is measured by means of a Heise-Bourdon pressure gauge. The components of the pressure-generating system (hand pumps, high-pressure tubing, valves, gauges, high-pressure separators) are available from several commercial sources. 

Gases are transferred in a standard Pyrex glass vacuum line equipped with high-vacuum stopcocks (lubricated with a fluorocarbon grease [Halocarbon]) to which is attached a four-trap system used for low-temperature trap-to-trap distillation (Fig. 1). Because of the reactivity of the compounds, a Heise-Bourdon tube gauge [Dresser Ind.], is used for PVT measurements. 

Fig. I. Standard Pyrex glass vacuum line a, thermocouple gauge [Fredericks] b, Heise-Bourdon tube gauge [Dresser] c, reservoir, 500 mL d, removable cold trap e, removable U-trap /, 18/9 ball-and-socket joint g, 2-mm Pyrex high-vacuum stopcock [Kontes] h, three-way high-vacuum stopcock i, Pyrex glass manifold, 10-12-mm diam j, Pyrex glass traps to fit into a standard Dewar flask k, 10/30 outer joint.

Freshly distilled sulfur dichloride (0.612 g, 6 mmol) and trimethylsilyl cyanide [Aldrich] (1.19 g, 12 mmol) are condensed at - 196° into a 50-mL Pyrex round-bottomed flask that is equipped with a Kontes Teflon stopcock to which is attached a 10/30 inner standard taper joint. A Teflon-coated stirring bar is placed in the vessel. The reaction vessel is connected to the vacuum line by a 10/30 outer Joint. The vacuum system is equipped with a Heise Bourdon tube gauge [Dresser Industries] and a Televac thermocouple gauge [Fredericks]. The quantities of SCI2 and (CH3)3SiCN are measured in the vacuum line by means of PVT techniques, assuming ideal gas behavior. 

The equilibrium pressure was read on a 0-3000 psig 16-in. Heise Bourdon tube gauge with 3-psi subdivisions, this gauge being thermally compensated and calibrated to an accuracy of 0.1 % of full scale. Thus the pressure readings may be considered accurate within 0.2 atm (3 psi). 

Keise - The name of the firm which manufactures the pressure gauges used to measure the water pressure in crossheaders at Hanford reactors. When speaking of a Heise the speaker is usually referring to the gauge for measuring water pressure at the reactor or to the actual monitoring procedure. 

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