SRS Labs SR530, Lock-In Amplifier manual

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attenuated by 6 dB/octave more. You may wish to use the bandpass filter and select a low dynamic reserve setting in order to achieve a better output stability. Since the processor can only set the bandpass filter's center frequency to within 1% of the reference frequency, this filter can contribute up to 5° of phase shift error and up to 5% of amplitude error when it is used. In addition, the bandpass filter adds a few nanovolts of noise to the front end of the instrument when it is in use.

Line Notch Filters should be used in most measurement situations. The filters will reject about 50 dB of line frequency noise (about a factor of 300). If your reference frequency is one octave away, then these filters will introduce a 5° phase shift error, and a few percent amplitude error. Their effect on your signal is negligible if your reference frequency is more than two octaves away.

The frequency range of the SR530 lock-in amplifier extends from 0.5Hz to 100KHz. No additional cards are required for the instrument to cover its full frequency range. The SR530 can be used to detect a signal at the reference frequency or at twice the reference frequency to allow for convenient measurement of the harmonic of the signal.

Output Filters can have one pole (6 dB per octave) or two poles (12 dB/octave). A two-pole filter provides a signal to noise improvement over a single-pole filter due to its steeper roll off and reduced noise bandwidth. Single-pole filters are preferred when the lock-in is used in a servo system to avoid oscillation.

In many servo applications, no output filtering is needed. In this case, the SR530 may be modified to reduce the output time constant to about 20 ∝ S. Contact the factory for details.

Noise measurement is a feature which allows direct measurement of the noise density of the signal at the reference frequency. This is a useful feature to assess at what frequency you should run your experiment.

Ratio Capability allows the lock-in's output to be divided by an external voltage input. This feature is important in servo applications to maintain a constant loop gain, and in experiments to normalize a signal to the excitation level.

Computer Interface allows a computer to control and to record data from the instrument. This is the single most important feature for extending the lock-in's capabilities and it's useful lifetime. Measurements which are impractical without a computer become simple when a computer is used to coordinate various parts of the experiment.

The Internal Oscillator provides a reference source for the lock-in. This allows the lock-in's frequency to be set without an additional signal generator. It also provides a sine wave to be used as the signal stimulus in an experiment. The frequency may be set via the computer interface as well as manually.

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Contents Model SR530 Page Table of Contents Appendix C Gpib NON-OPERATING OperatingPage SR530 Specification Summary Gpib DemodulatorFront Panel Summary Enbw Abridged Command List Status Byte Definition Configuration SwitchesSensitivity Signal InputsSignal Filters SR510 Guide to Operation Front PanelChannel 1 Display Dynamic ReserveStatus Display SelectOffset Channel OutputOutput Channel Rel ChannelChannel 2 Display Expand ChannelRcosø Output Auto Phase Trigger Level Rsinø OutputReference Input Time Constant Reference ModePhase Controls Reference DisplayLocal and Remote PowerDefaults SR530 Guide to Operation Rear Panel Page Front Panel Status LEDs Command SyntaxSR530 Guide to Programming Communicating with the SR530Try-Out with an Ascii Terminal RS232 Echo and No Echo OperationLOW Norm High SR530 Command ListN1,n2,n3,n4 Page Bit ErrorsStatus Byte Common Software Problems include ResetTrouble-Shooting Interface Problems Common Hardware Problems includeSR530 with the Gpib Interface SR530 with the RS232 InterfaceSR530 with Both Interfaces Serial Polls and Service RequestsGpib with RS232 Echo Mode Measurement Example Lock-in TechniqueShielding and Ground Loops Understanding the SpecificationsPage Page SR530 Block Diagram DC Amplifiers and System Gain Signal ChannelPhase Sensitive Detectors Reference ChannelCircuit Description Demodulator and Low Pass Amplifier Reference OscillatorMicroprocessor Control Analog Output and ControlExpand Front PanelGpib Interface Power SuppliesRS232 Interface Calibration and Repair Multiplier AdjustmentsAmplifier and Filter Adjustments Replacing the Front-End Transistors Notch FiltersNon-Essential Noise Sources Appendix a Noise Sources and CuresPage Page Case 2 RS232 with Control Lines Case 1 The Simplest ConfigurationAppendix B Introduction to the RS232 Baud RateFinal Tip Stop BitsParity Voltage LevelsBus Description Appendix C Introduction to the GpibProgram Example IBM PC, Basic, via RS232 Appendix D Program ExamplesProgram Example IBM PC, Microsoft Fortran v3.3, via RS232 Page #include stdio.h Program Example IBM PC, Microsoft C v3.0, via RS232Page Program Example 4 IBM PC,Microsoft Basic, via Gpib ′INCREMENT X6 Output by 2.5 MV Program Example HP85 via Gpib Documentation Dpdt Oscillator Board Parts ListPC1 SW1BT1 Main Board Parts ListBR1 BR2SR530 Component Parts List SR530 Component Parts List CX1 22U MINPIN D Gpib ShieldedMPSA18 CY1FU1 SR530 Component Parts List SR530 Component Parts List SR530 Component Parts List SR530 Component Parts List SR530 Component Parts List SR513 Assy SPSTX84PDT SR530 Component Parts List Static RAM, I.C Z80A-CPU#4 Flat TIE AnchorTranscover MicaFront Panel Board Parts List RED LD3 LD1LD2 Quad Board Parts List SR530 Component Parts List PC1 SR530 Component Parts List Miscellaneous Parts List SR530 Component Parts List

SR530, Lock-In Amplifier specifications

The SRS Labs Lock-In Amplifier, model SR530, is a powerful tool designed for high-precision measurements in the realm of scientific research and industrial applications. This state-of-the-art instrument excels in extracting small signals from noisy environments, making it an invaluable asset for experiments in fields such as physics, engineering, and materials science.

One of the main features of the SR530 is its ability to perform synchronous detection, which is key to improving signal-to-noise ratios. By utilizing a reference signal, the device correlates the incoming signal with the reference to effectively filter out noise, allowing for the accurate measurement of weak signals that might otherwise be obscured. This process of phase-sensitive detection is fundamental to the operation of the Lock-In Amplifier.

The SR530 offers a wide frequency range, covering from 0.1 Hz to 100 kHz. This broad frequency response allows it to handle a diverse array of signals, making it suitable for various applications including optical detection, capacitance measurements, and in many cases, voltammetry. The device is also equipped with multiple inputs and outputs, facilitating the integration with other laboratory equipment and enabling complex experimental setups.

Precision is further enhanced with its adjustable time constant, which allows users to optimize the response time based on experimental needs. The user can choose time constants from 10 microseconds to 10 seconds, accommodating fast dynamic measurements as well as those requiring stability over longer durations.

Another remarkable characteristic of the SR530 is its digital processing capabilities. The device features a highly accurate digital voltage measurement system, minimizing drift and ensuring long-term stability. Additionally, the use of microprocessors enhances data handling and allows for features such as programmable settings, facilitating automated measurements.

Moreover, the SR530 includes a range of output options, including analog outputs, which can be used for direct signal processing, as well as digital interfaces for integration with computers. This ensures that users can not only capture high-fidelity data but also analyze and display it efficiently.

In conclusion, the SRS Labs SR530 Lock-In Amplifier stands out due to its sophisticated technology, versatile features, and robust performance. Its precision, flexibility, and ease of use make it an ideal choice for researchers and engineers looking to unlock the potential of weak signal measurement in complex environments.
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