Overview
Over the past few years, the SIGNAL RECOVERY’ models 5209 (single-phase) and
5210 (dual-phase) have become the benchmark lock-in amplifiers against which others
are judged. They are widely referenced in technical publications describing a diverse
range of research applications including optical, electrochemical, electronic, mechanical
and fundamental physical studies.
Although more recently the introduction of instruments using digital signal processing
has brought advances in phase sensitive detection techniques, instruments using
analog demodulators are still the first choice for many experiments. These include those
requiring a true analog output, for example in some feedback control loops, or where the
instrument is used to recover the envelope modulation of a carrier frequency. Of course,
they are also chosen for compatibility with previous experimental setups.
Voltage or current inputs…
The instruments include a current preamplifier with two transimpedance settings and so
can directly measure signals from current sources such as photodiodes. With an input
impedance of down to typically only 25 Ω, the resulting voltage generated across the
source by the signal current is minimized for the very best performance.
Continuous full-scale sensitivity control…
As with all lock-ins the models 5209 and 5210 have a range of calibrated full-scale
sensitivity settings. However, unlike other units they also have a sensitivity vernier
control, allowing the full-scale sensitivity to be set to any value between the calibrated
values. Suppose you are performing an optical transmission experiment and you want
to measure transmission in terms of a percentage relative to that of a “reference”
sample. All you need to do is put the reference sample in the optical path and press the
auto vernier control on the lock-in. It will then adjust the sensitivity so that the display
reads 100%. Now replace the reference sample with the test sample and read the
percentage transmission directly.
Unique Walsh Function Demodulators…
The simplest method of implementing the phase sensitive detector at the heart of an
analog lock-in is with a reversing switch driven at the reference frequency, giving
excellent linearity, dynamic range and stability. This is known as a “squarewave”
demodulator since the instrument responds to signals not only at the reference
frequency but also at its odd harmonics. It offers much better performance than can be
achieved by using a true analog multiplier, which requires the synthesis of a very pure
reference sinusoid and is very nonlinear when handling large levels of interfering signal.
- 0.5 Hz to 120 kHz operation
- Voltage and current mode inputs
- Continuous full-scale sensitivity control
- Powerful fourth-order signal channel Bandpass, Low Pass or Notch filter
- Up to 130 dB dynamic Reserve
- Synchronous 15-bit ADC for lower input jitter
- Auger spectroscopy
- Feedback control loops
- Replication existing experimental setups
Over the past few years. the SIGNAL RECOVERY models 5209 (single-phase) and 5210 (dual-phase) have become the benchmark lock-in amplifiers against which others are judged.
Specifications
General
Dual-phase model 5210 analog lock-in amplifiers operating over a reference frequency range of 0.5 Hz to 120 kHz. Wide range of auxiliary inputs and outputs.
| Measurement Modes The model 5210 can simultaneously show one of these outputs on the front panel display: X In-phase R Magnitude 0 Phase Angle |
|
| Harmonic | F or 2F |
| Noise Measures noise in a given bandwidth centered at the reference frequency F |
|
| Displays Two 3½-digit LCD displays and analog panel meter |
|
| Signal Channel | |
| Voltage Input Modes |
A only or Differential (A-B) |
| Full-scale Sensitivity | 100 nV to 3 V in a 1-3-10 sequence and vernier adjustment |
| Max. Dynamic Reserve | > 130 dB |
| Impedance | 100 MΩ // 25 pF |
| Maximum Safe Input | 30 V pk-pk |
| Voltage Noise | 5 nV/√Hz @ 1 khZ |
| C.M.R.R. | > 100 dB @ 1 kHz |
| Frequency Response | 0.001 hz to 120 kHz |
| Gain Accuracy | 1% typical in Flat mode, 2% typical in tracking Bandpass mode |
| Gain Stability | 200 ppm/ºC typical |
| Distortion | -90 dB THD (60 dB AC gain, 1 kHz) |
| Grounding | BNC shields can be grounded or floated via 1 kΩ to ground |
| Current Input | |
| Mode | 10-6 A/V or 10-8 A/V |
| Full-scale Sensitivity 10-6 A/V 10-8 |
100 fA to 3 µA in a 1-3-10 sequence and vernier adjustment 1 -A to 300 µA in a 1-3-10 sequence and vernier adjustment |
| Max. Dynamic Reserve | > 130 dB |
| Impedance 10-6 A/V 10-8 A/V |
< 250 Ω at 1 kHz <2.5 kΩ at 100 Hz |
| Maximum Input | 15 mA continuous, 1 A momentary |
| Noise 10-6 A/V 10-8 A/V |
130 fA/√Hz at 1 kHz 13 fA/√Hz at 500 Hz |
| Frequency Response 10-6 A/V 10-8 A/V |
-3 dB at 60 kHz -3 dB at 330 Hz |
| Gain Accuracy | 1% typical in Flat mode, 2% typical in tracking Bandpass mode |
| Gain Stability | 200 ppm/ºC typical |
| Grounding | BNC shield can be grounded or floated via 1 kΩ to ground |
| Signal Channel Filters | |
| Line Frequency Rejection Filter Center frequency, F (factory set) Mode |
50/100 or 60/120 Hz |
| Main Signal Channel Filter Mode Frequency |
Fourth-order Low-pass, Bandpass, Notch or Flat (Disabled) Auto or Manual turning |
| Signal Monitor | Front-panel BNC connector allows viewing of signal immediately ahead of the demodulators(s) |
| Reference Channel | |
| TTL Input (rear panel) Frequency Range |
0.5 Hz to 120 kHz |
| Analog input (front panel) Impedance Level Frequency Range Squarewave input Level Frequency Range *Note: Lower levels can be used with the analog input at the expense of increased phase errors |
1 mΩ // 30 pF 1.0 V rms* 0.5 Hz to 120 kHz 250 mVrms* |
| Phase Set Resolution | 0.005º increments |
| Phase Set Accuracy | ± 1º |
| Phase Noise | 0.005º rms @ 1 kHz, 100 ms, 12 dB TC |
| Phase Drift | < 0.05º/ºC |
| Orthogonality (model 5210 only) |
± 0.5º above 5 Hz, degrading to ± 5º at 0.5 Hz |
| Acquisition Time | 100 ms + 2 cycles max |
| Lock Indicator | LED warns of frequency/phase unlock |
| Demodulator and Output Processing | |
| Mode | Sineware (Walsh demodulator + BP/LP filter) or Squarewave |
Zero stability /Dynamic Reserve
| Mode | Dynamic Reserve Filter On |
Dynamic Reserve Filter Off |
Zero Stability |
| High | 130 dB | 60 dB | 500 ppm/ºC |
| DR | |||
| Normal | 110 dB | 40 dB | 50 ppm/ºC |
| High | 90 dB | 20 dB | 5 ppm/ºC |
| Stability |
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| Harmonic Rejection | > 80 dB with Low-pass, and > 60 dB with Bandpass main signal filter |
| Output Filters Time Constant Roll-off |
1 ms – 3 ks (1-3-10 sequence) 6 dB/oct or 12 db/oct for all TC settings |
| Offset | Auto and Manual on X and/or Y: ±100% full-scale with Expand on) |
| Oscillator Frequency Range Amplitude Range Amplitude Resolution 0 – 500 mV 500 mV – 2 V |
0.5 Hz – 120 kHz 0 – 2 V rms (front panel or computer); 5 V rms fixed (computer only) 1 mV |
| Distortion (THD) | 0.5% |
| Output | sinewave from 900 Ω source |
| Auxiliary Inputs | |
| ADC 1, 2, 3 and 4 Maximum input Resolution Accuracy Input Impedance Sample Rate Trigger Mode Trigger Input |
±15 V 1 mV ±20 mV 1 MΩ // 30 pF 100 Hz Internal, External or ref synchronous TTL compatible |
| Outputs | |
| Demodulator Monitor | 100 µs TC @ 6 dB/octave (5210: X output only) |
| Main Analog (CH1 and CH2) Outputs | |
| 5210: | Two ±10 V FS (X, Y or R, 0) |
| Resolution | 1 mV |
| Impedance | 1 kΩ |
| Update Rate | 100 Hz |
| Expand | Expands X output by factor of 10 |
| Auxiliary D/A Outputs | |
| 5210 | One output, ±15 V |
| Resolution | 1 mV |
