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7210 Multichannel Lock-in Amplifier

7210 Lock-in Amplifier
Model 7210 Product Overview

The Model 7210 Multichannel Lock-in Amplifier is yet another example of the innovation and product development provided by Signal Recovery. This unique instrument is the first multichannel lock-in amplifier of its kind.

The design concept of the Model 7210 revolves around the idea of a single excitation signal combined with a multitude of detectors. So, the Model 7210 represents an economical solution compared to using a multitude of expensive amplifiers to work with each detector.

The main features & specification points are:
  • Each unit can be configured with 4, 8, 12, 16, 20, 24, 28, or 32 input channels
  • Up to sixteen units can be chain linked together, giving up to 512 input channels
  • Operates with an external reference only
  • Software controlled, without a front panel
  • Measured outputs are recorded digitally
  • Currently offer one type of signal input card:
    • Model 7210/99 option, which is a Voltage Input card
    • Operates at frequencies between: 20 Hz & 50.5 kHz
    • Sensitivity range of 100 uV to 1 V
  • Two choices of software solution:
    • SR7210Comms, which is an ActiveX software development toolkit
    • MULTILCOK software for a complete data acquisition solution (which includes SR7210Comms)
  • Documents +

  • Specifications +

    The signal input specifications depend on the type of signal board fitted, of which one option is currently available:
    7210/99 Signal Board - Voltage Mode Inputs

    Voltage Input
    Input Mode Virtual Ground


    Impedance Shell to Ground 0 Ohms
    Input Impedance 10 M Ohms
    Input Voltage Noise < 10 nVHz-0.5at 1 kHz
    Max Safe Input ± 12.0 V
    Frequency Response 20 Hz to 50.5 kHz
    Typical Gain Accuracy Overall ± 1.5%
    Typical Gain Match between Channels ± 3.0%
    Phase Accuracy Overall ± 2°
    Phase Match between Channels ± 1°
    Full-scale sensitivity 100 µV to 1 V rms in a
    1-3-10 sequence
    (9 settings)
    Reference Channel
    External Reference Input only
    Impedance 1 M Ohms//35 pF
    Level 250 mV to 2.5 V rms
    Connector BNC
    Frequency Range, F1 20 Hz to 50.5 kHz
    Lock Acquisition Time 2 sec (max)
    Reference Phase Shifter (each channel) Set Resolution 10 m°
    Orthogonality 90° ± 0.001°
    External Reference Frequency Meter Resolution 1 Hz
    Reference Output (Tandem frequency), F2
    F2 is F1/n, where n, an integer, is calculated by the instrument to give a frequency as
    close as possible to a user-specified value in the range 0.001 Hz to 100 Hz
    Amplitude > 3 V pk-pk square-wave
    Impedance < 200 Ohms
    Connector BNC
    Harmonic DetectionF and 2F
    2F (available in single-frequency operation only) 2F < 50.5 kHz
    Meter Resolution 0.001 Hz
    Main ADC’s, each channel 12 bit
    Sampling Rate 208 kHz < fs< 250 kHz,
    synchronous to external reference (F1) frequency
    Single-Frequency Operation
    Time Constants 4 ms to 1 ks in 1-3-10 sequence (12 steps)
    Slope 12 dB/octave
    Type Synchronous digital FIR filters
    Harmonic Rejection > 90 dB
    Dynamic Reserve > 80 dB
    Tandem-Frequency Operation
    Applying to F1 outputs:
    Time Constants 4 ms to 1 ks in 1-3-10 sequence (12 steps)
    Slope 12 dB/octave
    Type Synchronous digital FIR filters
    Harmonic Rejection > 90 dB
    Dynamic Reserve > 80 dB
    Applying to F2 outputs:
    Time Constants 30 ms to 1 ks in 1-3-10 sequence (11 steps)
    Slope 12 dB/octave
    Type Synchronous digital FIR filters
    Harmonic Rejection > 90 dB
    Dynamic Reserve > 80 dB
    Data Outputs
    The outputs available from the instrument are:
    Single Reference Mode X1 and Y1
    Tandem Demodulation Mode X1, Y1 and X2, Y2
    All outputs are for each of 32 channels. Outputs can be read directly on receipt of a command, or stored on receipt of a GPIB trigger or the GET command for later readout. The output values can be read using commands generating binary or ASCII responses.

    Instruments can be interconnected to provide more than 32 detection channels. Interconnections are via RG45 multipole connectors. Each instrument has a rear-panel switch to select whether the connectors function as outputs, in which case the unit is the "master", or inputs, when the unit is a "slave".

    Front-panel LEDs indicate the following conditions:
    Power On a single LED which is lit when line power is applied and the unit switched on
    Communications Activity indicates when command is being received and response is waiting to be read or being transmitted
    Master/Slave when lit indicates that the instrument is set to function as a "master" and that its synchronizing signal connectors are configured as outputs
    Internal Oscillator reserved for future expansion
    Reference Unlock lights when no suitable reference is applied
    Signal Channel Overload a single LED warning of input or output overload in any one of the 32 channels. It is possible to identify via a computer status command which channel(s) is affected and the type of overload condition
    Computer Interfaces GPIB (IEEE-488)
    and RS232
    Connectors Standard GPIB Centronics connector and
    9-pin female RS232
    Comms Settings Set by rear-panel DIPswitches
    Command Set ASCII commands for all instrument controls and data readout.
    Binary dump commands for data readout
    Power Requirements
    Voltage 100/120/220/240 V AC
    Frequency 50 - 60 Hz
    Power 200VA max
    Width 446 mm
    Height 3U (133.5 mm)
    Depth 435 mm
    Weight 12.5 kg
  • Options +

    In view of the specialized nature of this product, the model 7210 is currently available in 8 different configurations to meet individual requirements.
    The basic model 7210 will support up to eight signal boards, each with four signal channels. Orders can be placed as follows:
    Part Number Description
    7210 X4 4 Channel Voltage Input System
    7210 X8 8 Channel Voltage Input System
    7210 X12 12 Channel Voltage Input System
    7210 X16 16 Channel Voltage Input System
    7210 X20 20 Channel Voltage Input System
    7210 X24 24 Channel Voltage Input System
    7210 X28 28 Channel Voltage Input System
    7210 X32 32 Channel Voltage Input System
    When more than 32 channels are required then multiple systems can be supplied with 1 meter long interconnecting GPIB and reference link cables. Each instrument is of course supplied complete with a comprehensive instruction manual containing full programming information.
  • Software +

    Part Number Description
    SR7210Comms ActiveX and LabVIEW software development toolkit
    MULTILCOK Software for a complete data acquisition solution (which includes SR7210Comms)