Keithley 151(Model151Microvoltmeter) free download

File name 151(Model151Microvoltmeter).pdf

INSTRUCTION MANUAL MODEL 151 MICROVOLTMETER CONTENTS SECTION INTRODUCTION I SPJXIFICATIONS II Ranges Accuracy Input Xesl3t3ncs Overvoltage Zero Adjust Noise Zero Drift Response Speed Input Rejection In-Phase Rejection Impedance output Tube Complement power Connector3 Accessories Supplied Dimension3 OPERATION III Operating Control3 Preliminary Set Up Operation CIRCUIT DESCRIPTION Iv Input Circuit AC Amplifier Demodulator Circuit DC Amplifier Loop Description Power Supply MAINTENANCE General Trouble Shooting Procedure Replaceable Part3 List Voltage Resistance Diagram Circuit Schematic 151 0763 SECTION 1 - INTRODUCTION The Keithley Model 151 Null Detector is a stable, low-level DC amolimwith high-~<~utesistance and low noise. Careful shielding. fiitering, and gu&di.nk permit floating operation, as in a bridge nuli- detector, with excellent rejection to extraneous voltages. With a power sensitivity of lo-l7 watt, a re3pon3e speed of ""3 second, lack of overshoot and a zero-centered meter, the 151 may be used ,;n applications Inhere a suspension galvanometer might be employed, or in other applicaticns where a galvanometer is not sufficiently sensitive, fast or rugged. Five non-linear ranges are provided which have the same center- scale sensitiv'ty as the linear ranges, but are compressed in a quasi- logarithmi: way to three decade3 on each range. The3.e range3 permit speedier null-searching th3.n the l~inear scales, without sncrlfizing sensitivity at null. Two zero controls for opera 2.r.d short-circuit inputs ai~low prop3r zeroin,- for any Source resistance even in the presence of Bridge thermal emfts eliminating the need for disconnecting bri~di=e voltage cc set zerr). Although de?-:gned for nu?l detector applications, the Model 151 is also useful as a dc voltmeter with 3 maximum full-scale