Preamplifiers direct-current

Alternating-Current, Direct-Current, and Chopper-Stabilized Preamplifiers... 

Alternating-, Direct-Current and Chopper-Stabilized Preamplifiers 159... 

Time resolution is limited by the response speed of the detector and amplifier, and the speed of taking signals into the AD converter. If the pulse width of the external stimulus is short enough at a time resolution of about 100 ns, an absorbance change of smaller than 10 " is detectable [1]. In measurements using a photovoltaic MCT detector capable of producing output in both AC and direct current (DC) and a high-speed preamplifier [1,9], a time resolution of about 10 ns has been achieved. 

Where stray currents are involved, several measurements have to be taken that are continually changing with time, simultaneously with each other. A double recorder is most suitable for this. Linear recorders with direct indication of the measurements cannot be used for potential measurements because the torque of the mechanism is too small to overcome the friction of the pen on the paper. Amplified recorders or potentiometer recorders are used to record potentials. In amplified recorders, as in amplified voltmeters, the measured signal is converted into a load-independent impressed current and transmitted to the measuring mechanism, which consists of a torque motor with a preamplifier. The amplifier results in an... 

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