Instruments multimeter

Modern multimeters maybe equipped with memory possibilities, and/or interfaces to a personal computer by infrared, IrDA, or serial link, RS-232, or an instrument bus such as IEEE. Modern portable DMMs may have accuracies as good as 0.025%, whereas nowadays bench-top instruments reach accuracies in the single-digit parts per million figures. 

The rapid development of solid-state electronic devices in the last two decades has had a profound effect on measurement capabilities in chemistry and other scientific fields. In this chapter we consider some of the physical aspects of the construction and function of electronic components such as resistors, capacitors, inductors, diodes, and transistors. The integration of these into small operational amplifier circuits is discussed, and various measurement applications are described. The use of these circuit elements in analog-to-digital converters and digital multimeters is emphasized in this chapter, but modern integrated circuits (ICs) have also greatly improved the capabilities of oscilloscopes, frequency counters, and other electronic instruments discussed in Chapter XIX. Finally, the use of potentiometers and bridge circuits, employed in a number of experiments in this text, is covered in the present chapter. 

A contacting high voltage probe connected to a multimeter or similar laboratory instrument is fundamentally different from that of a an electrostatic... 

Scientific instruments Up to 50 W Oscilloscopes, multimeters, meteorological stations Central electricity grid, primary batteries Time of operation, volume + weight... 

For simple measurements a potentiostat and possibly separate multimeters for voltage and current measurements are adequate. For complicate experiments a function generator, an oscilloscope and a frequency response analyzer should be added to the system. When choosing an instrument one should check its capacity (operating rate, accuracy etc), n aintenance, compatibility with other devices and price. 

An electric field of 3V across the fingers with a gap size of 12mm was applied while the SWCNT samples were being coated on the IDE. Instrument used for the resistance measurement Keithley2002 digital multimeter and Agilent 34401 DMM. 

Must be able to use conventional electronic troubleshooting instruments such as multimeters, function generators, oscillators, and oscilloscopes. Should be able to use conventional machine shop equipment such as drill presses, grinders, belt sanders, brakes, and standard hand tools. 

The electrode current is measured through a Keithley 195 multimeter. Photon counting is done by a Keithley 795 A counter. Both instruments are connected to a personal computer by lEC BUS. Fluorescence intensity and electrode current were recorded with a time resolution of 0.5 s. 

Read precision instruments such as micrometers, dial indicators, bore gauges, volt- meters, digital multimeters, calibrators, and other electronic diagnostic tools. 

Logic probe functions. Signal high/low and pulse detection circuitry built into a DMM probe permits the instrument to function as both a conventional multimeter and a logic probe. This eliminates the necessity to change instruments in the middle of a troubleshooting sequence. 

MiUiammeter A test instrument for measuring electrical current, often part of a multimeter. Millihenry A quantity equal to one-thousandth of a henry. 

Multimeter A test instrument fitted with several ranges for measuring voltage, resistance, and current, and equipped with an analog meter or digital display readout. The multimeter is also known as a... 

An ammeter was shown in Fig. 2.2, with a separate battery and resistor attached to it. If all three are in a single plastic housing, a "multimeter" results, and an electrical diagram of such an instrument is shown in Fig. 2. 4. 

Set the multimeter controls (rotary switch or pushbuttons, depending on the particular instrument) to the direct current (dc) milliampere (ma) position, where the maximum amount of current is greater than what is expected in the experiment. If the Radio Shack meter. Catalog Number 22-218 is used, this will be the "150 mA DC" setting, since only about 50 ma is expected. 

The output of an ohmmeter does not necessarily have the same "polarity" as the red and black wires would usually symbolize for inputs. Looking at Fig. 2.4, it can be seen that the black wire should indeed have a positive output, relative to the other wire, when an external resistance is being measured. This can be shown experimentally by hooking up your ohmmeter to a neighboring experimenter s meter which has been set to be a voltmeter. It is not always true with other types of instruments, but it is often the case with inexpensive multimeters. 

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