SRS Labs Lock-In Amplifier, SR530 manual Appendix C Gpib

Page 4

Circuit Description

 

Introduction

34

Signal Amplifier

34

Current Amplifier

34

Notch Filters

34

Bandpass Filter

34

Reference Oscillator

35

PSD, LP Filters and DC Amplifier

35

Analog Output

36

A/D's

36

D/A's

36

Expand

36

Front Panel

36

Microprocessor Control

36

RS232 Interface

37

GPIB Interface

37

Power Supplies

37

Internal Oscillator

37

Calibration and Repair

 

Introduction

38

Multiplier Adjustments

38

Amplifier and Filter Adjustments

38

CMRR Adjustment

38

Line Notch Filter Adjustment

39

2xLine Notch Filter Adjustment

39

Repairing Damaged Front-End

39

Appendix A: Noise Sources and Cures

 

Johnson Noise

40

'1/f' Noise

40

Noise Spectrum

40

Capacitive Coupling

41

Inductive Coupling

41

Ground Loops

42

Microphonics

42

Thermocouple Effect

42

Appendix B: RS232

 

Simplest Case Using the RS232

43

Using Control Lines

43

Baud Rates

43

Stop Bits

44

Parity

44

Voltage Levels

44

'Eavesdropping'

44

Appendix C: GPIB

 

Introduction to the GPIB

45

Bus Description

45

Appendix D: Program Examples

 

Program Description

46

IBM PC, Microsoft Basic, via RS232

46

IBM PC, Microsoft Fortran, via RS232

47

IBM PC, Microsoft C, via RS232

49

ii

IBM PC, Microsoft Basic, via GPIB

51

HP-85, HP Basic, via HPIB

53

Documentation

 

Parts List, Oscillator Board

55

Parts List, Main Board

56

Parts List, Front Panel Board

70

Parts List, Quad Board

73

Parts List, Miscellaneous

77

Schematic Diagrams

79

Image 4
Contents Model SR530 Page Table of Contents Appendix C Gpib Operating NON-OPERATINGPage SR530 Specification Summary Demodulator GpibFront Panel Summary Enbw Abridged Command List Configuration Switches Status Byte DefinitionSignal Inputs Signal FiltersSR510 Guide to Operation Front Panel SensitivityDynamic Reserve StatusDisplay Select Channel 1 DisplayOutput Output ChannelRel Channel Offset ChannelRcosø Output Expand ChannelChannel 2 Display Auto Phase Reference Input Rsinø OutputTrigger Level Reference Mode Phase ControlsReference Display Time ConstantDefaults PowerLocal and Remote SR530 Guide to Operation Rear Panel Page Command Syntax SR530 Guide to ProgrammingCommunicating with the SR530 Front Panel Status LEDsRS232 Echo and No Echo Operation Try-Out with an Ascii TerminalSR530 Command List LOW Norm HighN1,n2,n3,n4 Page Status Byte ErrorsBit Reset Trouble-Shooting Interface ProblemsCommon Hardware Problems include Common Software Problems includeSR530 with the RS232 Interface SR530 with the Gpib InterfaceGpib with RS232 Echo Mode Serial Polls and Service RequestsSR530 with Both Interfaces Lock-in Technique Measurement ExampleUnderstanding the Specifications Shielding and Ground LoopsPage Page SR530 Block Diagram Signal Channel Phase Sensitive DetectorsReference Channel DC Amplifiers and System GainCircuit Description Reference Oscillator Demodulator and Low Pass AmplifierAnalog Output and Control ExpandFront Panel Microprocessor ControlRS232 Interface Power SuppliesGpib Interface Amplifier and Filter Adjustments Multiplier AdjustmentsCalibration and Repair Notch Filters Replacing the Front-End TransistorsAppendix a Noise Sources and Cures Non-Essential Noise SourcesPage Page Case 1 The Simplest Configuration Appendix B Introduction to the RS232Baud Rate Case 2 RS232 with Control LinesStop Bits ParityVoltage Levels Final TipAppendix C Introduction to the Gpib Bus DescriptionAppendix D Program Examples Program Example IBM PC, Basic, via RS232Program Example IBM PC, Microsoft Fortran v3.3, via RS232 Page Program Example IBM PC, Microsoft C v3.0, via RS232 #include stdio.hPage Program Example 4 IBM PC,Microsoft Basic, via Gpib ′INCREMENT X6 Output by 2.5 MV Program Example HP85 via Gpib Documentation Oscillator Board Parts List PC1SW1 DpdtMain Board Parts List BR1BR2 BT1SR530 Component Parts List SR530 Component Parts List 22U MIN PIN DGpib Shielded CX1FU1 CY1MPSA18 SR530 Component Parts List SR530 Component Parts List SR530 Component Parts List SR530 Component Parts List SR530 Component Parts List 4PDT SPSTX8SR513 Assy SR530 Component Parts List Z80A-CPU Static RAM, I.CTIE Anchor TranscoverMica #4 FlatFront Panel Board Parts List RED LD2 LD1LD3 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.