Automatic recording balance

Figure 1.3 Typical experimental arrangement for measuring oxidation kinetics with an automatic recording balance.

Svedberg and Rinde automatic recording sedimentation beam balance Cahn balance Gallenkamp balance Mettler H20E balance Sartorious Recording Sedibel balance... 

Thermogravimetric instrumentation should include several basic components in order to provide the flexibility necessary for the production of useful analytical data. These components are (a) a balance (b) a heating device (c) a unit for temperature measurement and control (d) a means for automatically recording the mass and temperature changes and (e) a system to control the atmosphere around the sample. 

Transactions File. A MeCtler Model PT320 balance having BCD output, and a CRT terminal are interfaced with the central computer through a microprocessor and the Varian HASP work-station. At the time sample weights are automatically recorded, the... 

Mettler produce two automatic titrimeters the DL 40 GP memotitrator and the lower-cost DL 20 compact titrator. Features available on the DL 40GP include absolute and relative end-point titrations, equivalence point titrations, back-titration techniques, multi-method applications, dual titration, pH stating, automatic learn titrations, automatic determination of standard deviation and means, series titrations, correction to printer, acid balance analogue output for recorder and correction to the laboratory... 

In balances which give two TG-curves with different sensitivity, an electrical compensation device switches automatically the expanded curve to the next passage in the chart strip (see Fig. 7 with the two recorded TG-curves). 

Hydrogen gas is released in the reaction. You can track the decrease in mass, due to the escaping hydrogen, by carrying out the reaction in an open vessel on an electric balance. The decrease in mass can be plotted against time. Some electronic balances can be connected to a computer, with the appropriate software, to record mass and time data automatically as the reaction proceeds. 

In order to eliminate the necessity of removing the sample from the constant temperature chamber for weighing Guichard [91] introduced the use of an automatic balance which allows the weight of the sample to be recorded continuously. 

Loss of catalyst from the unit is measured by changes in inventory in the vessels and by the additions of make-up catalyst. Accuracy of the measurement from day to day is not high, but reliable data are accumulated over a period of time. An instrument has been developed for continuous recording of catalyst loss from the stack, which consists of an optical device (light source and thermopile) to measure concentration of solids, and a flowmeter to measure the flue-gas rate (268). The two devices are coupled by a mechanism which automatically multiplies catalyst concentration by the gas-flow rate. Catalyst carry-over from the regenerator of a unit equipped with a Cottrell precipitator has been measured by heat balance in the catalyst-return line from the Cottrell to the regenerator (34). 

Whether background correction needs to be applied depends on the separation system employed. If the instrument is balanced properly, then, for isocratic separations, the solvent background will be eliminated by the built-in automatic subtraction of the solvent spectrum, as present at the beginning of the analysis, from all recorded spectra. For gradient separations, background corrections will have to be applied after the analysis. 

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