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home > Products > Measurement Instruments > Lock-in Amplifier/Preamplifier > Lock-in Amplifier > LI5640/LI5630 > Features
Product Information
Lock-in Amplifier/Preamplifier
Digital Lock-in Amplifier
LI 5640
High stability
The amplifier features high stability and low drift designs in which all processes have been digitized except for the preamplifier used for input. Zero output drift was reduced to miniscule levels in the high sensitivity regions. Phase stability is 0.01°/°C and gain stability is ±100 ppm/°C. This high stability has formed the backbone for high resolution of 4 1/2 digits and the low noise levels indicated by input referred noise voltage of 4.5 nV/ √Hz and phase noise of 0.001°. These features enable very reliable small signal measurements.

Measurement is possible starting from 1 mHz
Measurement is possible from 1 mHz, something that could never be achieved with analogue lock-in amplifiers. A new way has been paved for low-speed phenomenon analysis, such as infrared spectroscopy and temperature response. Digital systems naturally allow high stability. You need never worry about drift in measurements. It is also to the advantage of low frequency measurements that signals are locked to the reference signal in approximately two periods.

Prompt and smooth responses
" Prompt and smooth measurement responses "
The minimum time constant for the wave detection part is 10µs. D/A conversion of direct current output is possible with high speed and accuracy, at up to 256k samples/sec and 16 bit. Responses are prompt not only for X-Y but also for R-θ output. Up to 16k samples/second is possible for recording with digital data memory. Moreover, the amplifier features the new synchronized filter, which allows a moving average to be maintained with signal period. Ripples in measurement are significantly reduced, even with small time constants. In addition, the synchronized filter can be used in all frequency ranges. We invite everyone to enjoy fully the prompt and smooth responses.

" Instantaneous responses when settings are switched "
Even when the settings for phase and sensitivity are changed during a measurement, the latest value is converted to the value for the new setting, allowing instantaneous responses for measurement. Even when the time constant is large, you need not wait for the time constant response.

Easy operation
The amplifier features a one-way set up for signal input, filter, dynamic reserve, sensitivity and time constants, in that order from left to right. Because it is easy to see the key arrangement, errors in settings are prevented. The auto-set button is convenient for setting unknown input signals.
There are three sets of large displays. They ensure accurate reading of settings and measurements. In addition, modify dial and analogue meters are also provided. You can enjoy the capabilities of the digital lock-in amplifier in an analogue style.

Line-up of two products
There are two models available for the product, namely the multi-functional and fully equipped digital lock-in amplifier LI 5640 and the economic digital lock-in amplifier LI 5630 with the same basic performance but of simpler functional line-up. Both models are of two-phase type.

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