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Recording balances

Recording balances can be divided basically into two general classifications, based on their mode of operation (I) deflection-type instruments and (2) null-type instruments (2). [Pg.89]

The helical spring, in which changes of mass are detected by contraction or elongation of the spring and which may be recorded by suitable transducers. [Pg.90]

The cantilevered beam, constructed so that one end is fixed and ihe other end, from which ihe sample is suspended, is free to undergo deflection. [Pg.90]

The suspension of a sample by an appropriately mounted strain gauge that stretches and contracts in proportion to mass-changes. [Pg.90]

The attachment of a beam to a taut wire which serves as the fulcrum and is rigidly fixed at one or both ends so that deflections are proportional to the changes in mass and the torsional characteristics of the wire. [Pg.90]


SORPTION EXPERIMENTS. Sorption experiments were carried out using a Cahn 1000 recording balance, with an accuracy of 0.03 mg. The balance and its accessories are shown in Figure 1. The instrument is equipped with an MKS Baratron pressure transducer (0-100 torr, 0.15% accuracy) with a digital readout for pressure measurements. [Pg.140]

As shown in Fig. 4.8.1, a TG apparatus typically consists of a (1) recording balance, (2) furnace, (3) furnace temperature controller, (4) temperature programmer, (5) temperature detector, and (6) recorder. Most commercial models, e.g., Perkin-Elmer Model TGA-7, TA Instruments 2950 TGA, Mettler TC11ATG50, Seiko Instruments SSC 5200 TG-DTA 220, and Shimadzu TGA-50, consist of these basic components. [Pg.200]

A thermobalance can be one of three types according to the position of the furnace in relation to the recording balance (1) below balance, (2) above... [Pg.200]

Fig. 4.8.1. Schematic diagram of a TG apparatus, recording balance (/), furnace (2), furnace temperature (5), temperature programmer (4), temperature detector (5), and recorder (6)... Fig. 4.8.1. Schematic diagram of a TG apparatus, recording balance (/), furnace (2), furnace temperature (5), temperature programmer (4), temperature detector (5), and recorder (6)...
The thermocouple is in close proximity to the sample in (b) and is positioned inside, but not in contact with, the sample holder. This arrangement is better than (c) because the thermocouple will respond to small changes of sample temperature. The best method of sample temperature detection is to have the thermocouple either in contact with the sample or with the sample container, as shown in (c). In the latter, the temperature detected will be the integrated temperature. However, the main problem is that with sensitive recording balances the thermocouple leads can cause weighing errors, or at least interference with the balance mechanism. One way to detect the actual sample temperature and yet not interfere with the balance mechanism is to suspend an electronic device near the sample holder which will transmit the sample temperature to a fixed receiver located near the sample container. Manche and Carroll (13) described a unijunction transistor relaxation oscillator which used a thermistor as the temperature detector. The frequency of oscillation, which is a function of sample temperature, was transmitted via a mutual inductance between two suspended coils to a receiver and counter. The device was limited, however, to a maximum temperature of about 150°C. [Pg.100]

Figure 3.32. An automated thermobalance, (a) Balance, furnace, and sample changer mechanism (ft) furnace and sample holder (50). ( ) A. gas flow-meter B. furnace C. sample-holder disk D. cooling fan E, Cahn Model rtl recording balance F. balance platform, (ft) A. gas inlet tube B, thermocouples C. furnace heater windings and insulation D. sample container E. sample-holder disk F. ceramic sample probe. Figure 3.32. An automated thermobalance, (a) Balance, furnace, and sample changer mechanism (ft) furnace and sample holder (50). ( ) A. gas flow-meter B. furnace C. sample-holder disk D. cooling fan E, Cahn Model rtl recording balance F. balance platform, (ft) A. gas inlet tube B, thermocouples C. furnace heater windings and insulation D. sample container E. sample-holder disk F. ceramic sample probe.
This kinetic study of catalyzed hydrogasification reactions utilizes a high temperature, high pressure recording balance. A thermobalance is particularly useful in gas-solid reactions because the weight of small solid samples can be measured continuously. Direct kinetic analysis of the weight loss curves are straightforward. [Pg.227]

Figure 1.3 Typical experimental arrangement for measuring oxidation kinetics with an automatic recording balance. Figure 1.3 Typical experimental arrangement for measuring oxidation kinetics with an automatic recording balance.
The high pressures used in mercury porosimetry gives erroneous results with deformable material such as fabric. A more general version of liquid porosimetry, based on the same principles, uses a variety of liquids and can be carried out in the extrusion mode [79,80]. In this technique, a pre-saturated specimen is placed on a microporous membrane supported on a rigid porous plate in an enclosed chamber. The gas pressure within the chamber is increased in steps causing the liquid to flow out of the pores. The amount of liquid removed is monitored by a top-loading recording balance. One also has the... [Pg.182]


See other pages where Recording balances is mentioned: [Pg.72]    [Pg.322]    [Pg.123]    [Pg.128]    [Pg.201]    [Pg.20]    [Pg.169]    [Pg.352]    [Pg.358]    [Pg.188]    [Pg.414]    [Pg.421]    [Pg.188]    [Pg.47]    [Pg.158]    [Pg.11]    [Pg.32]    [Pg.87]    [Pg.89]    [Pg.89]    [Pg.112]    [Pg.127]    [Pg.740]    [Pg.6]    [Pg.6]    [Pg.145]    [Pg.117]    [Pg.42]    [Pg.22]    [Pg.539]    [Pg.22]    [Pg.221]    [Pg.322]    [Pg.366]    [Pg.428]   
See also in sourсe #XX -- [ Pg.89 ]

See also in sourсe #XX -- [ Pg.209 , Pg.210 , Pg.212 ]




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Automatic recording balance

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