Pump microprocessor

Since 1970, new analytical techniques, eg, ion chromatography, have been developed, and others, eg, atomic absorption and emission, have been improved (1—5). Detection limits for many chemicals have been dramatically lowered. Many wet chemical methods have been automated and are controlled by microprocessors which allow greater data output in a shorter time. Perhaps the best known continuous-flow analy2er for water analysis is the Autoanaly2er system manufactured by Technicon Instmments Corp. (Tarrytown, N.Y.) (6). Isolation of samples is maintained by pumping air bubbles into the flow line. Recently, flow-injection analysis has also become popular, and a theoretical comparison of it with the segmented flow analy2er has been made (7—9). 

The speed of an electric motor can be changed by altering the frequency of the electric current. This is because the ratio is the same as 60 or 50 f/p (f = the frequency of the current, p = the number of poles in the stator). Frequency converters are built of electronic components, frequently combined with microprocessors. They provide good motor protection and are superior to the traditional bimetal protection. The characteristic curve for a pump and fan motor is also quadratic, making lower demands to the frequency converters When the frequency of the electrical current is changed in the frequency converter, the main AC supply is transformed into DC. The DC is then treated... 

Superior hardware to the traditional apparatus is readily available and in some cases microprocessor intelligence is being built into dedicated modules for say temperature or pumping control. Integration of such units has the potential of full automation. 

Flow injection analysis (FIA) (Ruzicka and Hansen), since 1975 In continuous flow, stopped flow or with merging zones (FIA scanning or intermittent pumping) Adapted voltammetric electrodes Membranes for Partial dialysis Membrane amperometry (Clark) Differential techniques (Donnan) Computerization, including microprocessors Special measuring requirements in plant control (to avoid voltage leakage, etc., Section 5.5)... 

The very low storage temperature and low operating temperature specifications (see Section 4.3 below) also required dedicated design features because many of the components, such as the pumps and processors, cannot operate at very low temperatures. Because of this limitation there were added to several components cold start heaters controlled by snap switches. Further, an industrial temperature grade microprocessor was used in the SDU. With the snap switches the cold start heaters can come on when the power is applied at less than about 32°F/0°C. The snap switches cut off the cold start heaters and apply power to the full CBMS II system once their setpoint temperature is reached. 

Fig. 2.1 Schematic diagram of the CMR [22]. 1, reactants for processing 2, metering pump 3, pressure transducer 4, micro-wave cavity 5, reaction coil 6, temperature sensor 7, heat exchanger 8, pressure regulator 9, microprocessor controller ...

Sakamoto et al. [143] described an automated, near real-time analysis with microprocessor-controlled syringe pump modules for the determination of... 

Where binary, ternary or quaternary gradient elution (p. 91) is required, a microprocessor controlled low-pressure gradient former is the most suitable (Figure 4.31(c)). The solvents from separate reservoirs are fed to a mixing chamber via a multiport valve, the operation of which is preprogrammed via the microprocessor, and the mixed solvent is then pumped to the column. For the best reproducibility of solvent gradients small volume pumps (< 100 gl) are essential. 

Figure S.ll shows the flow diagram of the microprocessor-controlled preconcentration equipment, which is configured here for off-line operation, and consists of a sample changer, three separate peristaltic pumps (PI, P2 and P3) for the sample solution, buffer and add, three magnetic valves (VI, V2 and V3), the preconcentration column filled with chelating ion-exchange material (7 mm i.d., 10—30 mm height) and a fractionating unit for the addic column eluate. The flow-rates for the sample solution, buffer and add are adjusted to S ml/min.

Most of the autosamplers have a piston metering S3rrmge t)rpe pump to suck the preestablished sample volume into a line and then transfer it to the relatively large loop ( 100 ml) in a standard six-port valve. The simplest autosamplers utilize the special vials with pressuarization caps. A special plunger with a needle, push the cap down to the vial and displace the sample through the needle into the valve loop. Most of the autosamplers are microprocessor controlled and can serve as a master controller for the whole instrument... 

The front panel of the controller has two four-digit thumbwheel switches and two lighted pushbutton switches. The thumbwheels determine flow rate (ml/min) and volume to be delivered (ml). One pushbutton switch initiates the pump-refill operation. The other starts the injection, or stops an injection in progress. After power-up or reset, the microprocessor initializes itself and sets up the timing module and serial ports. It then jumps into a looping program that scans the two pushbutton switches and the... 

Does the customer s management fully understand what is required from their side and can they actually deliver the necessary supervisory and manpower support For example, changing from a system of simple chemical dosing pumps to a microprocessor-controlled product residual tracing and addition system will probably require more equipment inspection and calibration time. It will also require a high degree of instrumentation skill. 

Pressures within the optical cells are adjusted using a microprocessor-controlled supercritical fluid syringe pump (Isco model SFC-500). The temperature of the cylinder head is regulated using a VWR 1140 temperature bath. The output from the pump is directed through a 2 /xm fritted filter and a series of valves into the optical high pressure cell which is temperature controlled ( 0.1 °C) by a Lauda RLS-6 temperature bath. The local temperature of the optical cell is determined using a thermocouple (Cole Palmer) placed directly into the cell body. 

Orion amperometric gas diffusion sensor (Clark electrode), Crison GPL 22 pHmeter, potenziometer (microprocessor ionoanalyzer/901 Orion Research), Amel recorder mod. 868, peristaltic pump (Miniplus 3 Gilson). 

Blanco and Samadani37 obtained a patent for the construction of a microprosessor-based insulin pump that works in a similar fashion to the Biostator. The implantable infusion device consists of a catheter, an information-transmitting sensor located in the catheter, a microprocessor, a pump, the drug reservoir, and a power source. The pump, the sensor, and the valves are connected by appropriate leads to the microprocessor. The device is implanted in the subcutaneous tissue in the chest area, and the infusion catheter is tethered intravenously to a central location, such as the right atrium. The device is inserted with the inlet port facing outward so that it may be refilled periodically by a physician. 

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