Signal amplifier 420

differentialanaloglock-in

Scitec Instruments Model 420 is a dual phase analogue lock-in amplifier. Both the single phase Model 410 and dual phase Model 420 are suitable for making amplitude and phase measurements but it is significantly easier with the Model 420. • Dual phase instrument • Differential or single-ended input • Gain settings from 3 µV to 1 V • High performance wide bandwidth input gain stage • Analogue meter for display of output signals • Output offset controls • Output time constants from 100 µs to 30 s • 1F and 2F reference signal operation • 90° step and fine phase control Scitec Instruments lock-in amplifiers are available as both single phase and dual phase instruments. Single phase lock-in amplifiers have a single demodulator and can be used to make both amplitude and phase measurements. However a manual set-up procedure is required both initially and following any phase change of the output signal. Dual phase lock-in amplifiers have two demodulators which operate with a 90° phase separation. In-phase and out-of-phase components are measured simultaneously which simplifies the process of making amplitude and phase measurements. In addition the Model 420 has circuitry for calculating the vector magnitude from the output of the two demodulators. The Model 420 instruments can be used to make measurements of the input signal at both the first and second harmonic of the reference signal.