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7270 General Purpose DSP Lock-in Amplifier

7270 has both computer-control with Ethernet, USB and front-panel control 

Our lock-in amplifier software

  • Highlights +

    • Virtual Front Panel for low profile design to support integration into larger systems 
    • Dual reference and dual harmonic detection allow signals at two different frequencies to be measured simultaneously
    • Upgradable to 250kHz with typical configuration range from 120 kHz to 1 mHz
    • Ethernet connectivity for flexible, simple browser control
    • Compact design has no mechanical fans so it is completely silent, especially useful for acoustic research

  • Lock-in Amplifiers +

    Lock-in Amplifiers
    Signal Recovery originated from the Princeton Applied Research, EG&G products for scientific instrumentation.  They are the inventors of the lock-in amplifier.  A lock-in amplifier is an instrument with dual capability.  It can recover signals in the presence of an overwhelming noise background or, alternatively, it can provide high resolution measurements of relatively clean signals over several orders of magnitude and frequency.
  • Software +

    Acquire Data Acquisition Software

    Compatible Instruments:  Acquire will operate the current SIGNAL RECOVERY Models:  7124, 7225, 7230, 7265, 7270, and 7280
    As well as the legacy models:  4161A, 5105, 5113, 5210 and others.
    Up to ten instruments can be operated simultaneously.

    Acquire is a comprehensive data acquisition package designed to operate most current and many former SIGNAL RECOVERY instruments from a personal computer. It is suitable for use with all our lock-in amplifiers, boxcar averager, and 5113 preamplifier, and operates via Ethernet, USB, RS232, or GPIB (IEEE-488) interfaces. For most users, the software eliminates the need for them to write control software, so that they can concentrate on the task of taking data. It will also prove invaluable for others who simply want to operate an instrument from a remote location or who wish to integrate their instrument with other computer controlled systems. Up to ten instruments can be controlled at the same time.

    The package provides two principal modes of operation. First, in remote front panel mode virtually all of the functions of the connected instrument(s) can be controlled from the computer via a series of simple dialogs. The software is instrument sensitive and adjusts the content of these dialogs automatically to reflect the measurement capabilities and functions available in the connected unit. The data outputs to be displayed can be chosen from the range available and these are then clearly shown on-screen.

    The second mode, experiment recording, allows selected instrument outputs to be recorded as a function of time, with the additional option of sweeping certain outputs (e.g. oscillator frequency, auxiliary DAC voltage, digital filter frequency, digital delay and/or digital port setting) as the experiment proceeds. When used with a lock-in amplifier, any auxiliary ADC inputs can be configured as trigger inputs, allowing data to be logged as function of external trigger events.

    As data is acquired, it is displayed on screen and can be printed, as well as being saved for later use. Displayed plots can use a variety of line formats, while four curve cursors allow direct readout of measured values. However, with the very wide range of applications in which SIGNAL RECOVERY instruments can be used, it is not possible to anticipate every possible format in which the acquired data will be displayed. Hence many users take advantage of the export function to save the data to disk for display and/or further manipulation using other software.

    A comprehensive help system is built in and free support is available to registered users.


    SRInstComms is an ActiveX control that allows users of SIGNAL RECOVERY instruments to control them from PC’s running Windows Operating Systems. The requirement is that these programs must be written in a language that supports such controls, which in practice is virtually all modern languages capable of developing Windows applications. 

    The control takes care of all communication between the user-developed program and the instrument, performing the necessary handshaking and decoding status signals over the selected interface, which can be GPIB, RS232, Ethernet or USB, depending on the type of interface fitted to the instrument being controlled. With the exception of speed, the interface type is essentially transparent to the user, making programs portable between systems with different interfaces. 

    It includes an automatic search routine which will find any compatible instruments that are connected to the computer. In most cases, this eliminates the need to adjust the communications settings controls on the instrument. The complete “profile” of connected instruments, together with any user-entered descriptive comments, is then securely saved in the system registry. Subsequent data transmissions to and from the instrument use this information to give the fastest possible communication. 

    Up to ten compatible instruments can be controlled independently or simultaneously, so that for example in a system measuring impedance one lock-in amplifier can measure the sample current while a second measures the voltage. Both instruments can be read via the control and the output readings combined to determine the impedance. 

    The package includes a full printed instruction manual, as well as on-screen help so that programming information is always easily available. In addition, sample applications in Visual Basic, Visual C++, Visual C#, LabVIEW, Excel and VBScript (HTML web page) are supplied. The VB, Visual C++ and Visual C# examples include a working executable as well as a full project workspace with all the corresponding source files. Similarly the LabVIEW, Excel and VBScript demonstration programs are complete with all source code information so that they can be easily edited by the user. 
  • Brochure and Manual +

  • Differentiated Specifications +

    Signal Channel
    Voltage Input
    Modes A only, -B only or Differential (A-B)
    Freq. Response 1 mHz < F < 250 kHz
    Full-scale Sensitivity 2 nV to 1 V in a 1-2-5 sequence (e.g. 2 nV, 5 nV, 10 nV, 20 nV, etc.)
    Z - FET 10 MΩ // 25 pF, AC or DC coupled
    Z - Bipolar 10 kΩ // 25 pF, input must be DC coupled
    Max safe input ±12.0 V
    Vin Noise - FET 5 nV/√Hz @ 1 kHz
    Vin Noise - Bipolar 2 nV/√Hz @ 1 kHz
    C.M.R.R. > 100 dB @ 1 kHz degrading by > 6 dB/octave with increasing frequency
    Gain Accuracy ±0.5% typ, ±1.0% max
    Distortion -90 dB THD (60 dB AC gain, 1 kHz)
    Current Input
    Mode Low Noise (10E8 V/A) or Wide Bandwidth (10E6 V/A)
    Full-scale Sensitivity
    Low Noise 2 fA to 10 nA in a 1-2-5 sequence
    Wide Bandwidth 2 fA to 1 µA in a 1-2-5 sequence
    Frequency Response (-3 dB):
    Low Noise 1 mHz < F < 500 Hz minimum
    Wide Bandwidth 1 mHz < F < 50 kHz minimum
    Low Noise < 2.5 kΩ @ 100 Hz
    Wide Bandwidth < 250 Ω @ 1 kHz
    Low Noise 13 fA/√Hz @ 500 Hz
    Wide Bandwidth 130 fA/√Hz @ 1 kHz
    Gain Accuracy ±2.0% typ, midband
    Max. Dynamic Reserve > 100 dB
    Grounding BNC shield can be grounded or floated via 1 kΩ to ground
    Signal Monitor Amplitude ±1 V FS
    Output Impedance 1 kΩ
    Reference Channel
    Reference Input
    Frequency Range 1 mHz to 250 kHz
    Analog Input (front panel)
    Impedance 1 MΩ // 30 pF
    Sinusoidal Input Level 1.0 V rms*
    Frequency Range 0.5 Hz to 250 kHz
    Squarewave Input Level 250 mV rms
    Frequency Range 2 Hz to 250 kHz
    Reference Channel
    Phase Set Resolution 0.001° increments
    Phase Noise at 100 ms TC, 12 dB/octave slope:
    Internal Reference < 0.0001° rms
    External Reference < 0.01° rms @ 1 kHz
    Orthogonality 90° ± 0.0001°
    Acquisition Time
    Internal Reference instantaneous
    External Reference 2 cycles + 1 s
    Demodulator and Output Processing
    Harmonic Rejection -90 dB
    Output Filters
    Time Constant 10 µs to 100 ks in a 1-2-5 sequence
    Slope (roll-off):
    TC < 5 ms 6 or 12 dB/octave
    TC > 5 ms 6, 12, 18 or 24 dB/octave
    Synchronous Filter Available for F < 20 Hz
    Offset Auto and Manual on X and/or Y: ±300% full-scale
    Phase Measurement Resolution < 0.01º
    Oscillator - General
    Freq. Range 1 mHz to 250 kHz
    Setting Resolution 1 mHz
    Absolute Accuracy ± 50 ppm
    Amplitude Range 1 µV to 5 V
    Max. Setting Resolution 1 µV
    Output Impedance 50 Ω
    Frequency Sweep
    Output Range 1 mHz to 250 kHz
    Law Linear or Logarithmic
    Step Rate 1 kHz maximum (1 ms/step)
    Amplitude Sweep
    Output Range 0.000 to 1.000 V rms
    Law Linear
    Step Rate 20 Hz maximum (50 ms/step)
    Oscillator Output
    Accuracy ±0.2% typ
    Stability 50 ppm/ºC
    Distortion (THD) -80 dB @ 1 kHz and 100 mV rms
    Data Storage Buffer
    Size 100,000 data points
    Max. Storage Rate
    Fast Mode up to 1 MHz (X1, Y1, X2, Y2, ADC1, Demod I/P 1, Demod I/P 2)
    Normal Mode 1 kHz
    User Settings
    Up to 8 complete instrument settings can be saved or recalled at will from non-volatile memory
    USB 2.0, Ethernet, and RS232 allow complete control of instrument settings, and data readout.
    Power Requirements
    Voltage 110/120/220/240 VAC
    Frequency 50/60 Hz
    Power 40 VA max
    Width 15½" (390 mm)
    Depth 7¼" (185 mm)
    With feet 7¼" (185 mm)
    Without feet 6½" (170 mm)
    Weight 12.8 lb (5.8 kg)
    Specifications subject to change without notice
  • Differentiated Specifications +

     Specifications  7270 7230 7280 7265  7225 
    Dual Reference,
    Dual Harmonics
    YES YES  YES to 20 kHz
    Option to 800 KHz
    or 2 MHz
    YES to 20 kHz NO
    Connectivity Ethernet,
    Frequency Range
    (X to 1 mHz)
    120 kHz
    optional 250 kHz
     250 kHz 2 MHz to 0.5 Hz 250 kHz  120 kHz  
    Dynamic Reserve   100 dB for 1 nV / √ Hz
    Types of References Internal, External
    with Virtual
    Internal, External 
    with Virtual
    Internal, External  Internal, External  Internal, External 
    Control Interface Computer Controlled  Computer Controlled,
    Full Front Panel
    Computer Controlled,
    Full Front Panel
     Computer Controlled, 
    Limited Front Panel
    Computer Controlled,
    Limited Front Panel
  • Accessories +

  • Optional Software +