Additional Features: 1 mHz to 102.4 kHz frequency range >100 dB dynamic reserve 5 ppm/°C stability 0.01 degree phase resolution Auto-gain, -phase, -reserve and -offset Synthesized reference source GPIB and RS-232 interfaces The Stanford Research Systems SR830 Lock-In Amplifier provides high performance at a reasonable cost. The SR830 simultaneously displays the magnitude and phase of a signal.  The SR830 uses digital signal processing (DSP) to replace the demodulators, output filters, and amplifiers found in conventional lock-ins. The SR830 provides uncompromised performance with an operating range of 1 mHz to 102 kHz and 100 dB of drift-free dynamic reserve.