OE1022 detects an input signal in a single-ended mode or a differential voltage mode. With an ultra low-noise preamplifier, the input noise is as low as 6 nV/√Hz@997 Hz. The input impedance is 10 M? and the full-scale input voltage sensitivity ranges from 1 nV to 1 V. Besides, OE1022 can be used for current measurement with gains of 10 or 10 V/A. Two line filters (50/60 Hz and 100/120 Hz) are designed to eliminate power frequency interference. A programmable gain amplifier is used to adjust the dynamic reserve of the system, so that OE1022 can keep a high dynamic reserve of 100 dB. The high-precision 24-bit ADC has a sampling rate of 312.5kSPS, and the excellent antialiasing filter in front of the ADC can effectively prevent signal aliasing.
The reference signal can work in external mode or internal mode. In internal mode, a precise and stable internal oscillator generates sine wave as an internal reference that is multiplied by the input signal. This internal signal is without any phase noise. With the digital phase-shifting technique, the phase resolution of the reference signal is 0.01°. OE1022 can work at any fixed frequency from 1 mHz to 102 kHz in this mode. In external mode, the reference signal can be a sine wave or a TTL pulse or a square wave. The rising or falling edge of the external reference signal triggers the Phase Lock Loop (PLL) to lock the external signal. Based on the frequency of the reference signal, the OE1022 can detect the harmonics of the input signal. The maximum harmonic signal frequency can reach 32,767 times the fundamental frequency, and the maximum harmonic frequency cannot exceed the maximum operating frequency of the instrument by 102 kHz.
OE1022 uses the 5.6 inch 640×480 TFT color display as its screen. Data measured by OE1022, such as, X, Y, R, θ, is stored in up to four traces. Trace values can be displayed as a bar graph or as a strip chart showing the trace values as a function of time.
OE1022 can also show the relationship of time and range in a XY graph and you can check the value of sampling point by using knob control cursor.
Besides, OE1022 can display polar plots, showing phasor composed by in-phase and quadrature components of the signal. All displays can be easily scaled by the manual operation, and the auto-scale feature is available to optimize display quickly. The screen can be configured as a single large display, or two horizontally-split displays.
Simultaneous Multiple-harmonic Measurement
In the traditional lock-in amplifiers, only the fundamental frequency signal or a certain harmonic signal can be measured at one time, so it cannot meet the requirement of multiple-harmonic measurement in some occasions. On the contrary, OE1022 uses a flexible digital framework combined FPGA and ARM, which make it practicable and efficient to measure 3 harmonic components simultaneously, which means that one OE1022 is equivalent to three traditional lock-in amplifiers. The maximum harmonic signal frequency can reach 32,767 times the fundamental frequency, but the maximum harmonic frequency cannot exceed the maximum operating frequency of the instrument by 102 kHz.
Users can use PC to control OE1022 through communication interfaces, including setting the parameters and reading the measurement data. OE1022 is equipped with a free LabVIEW program, which makes it easy to use in complex scientific experiments.