SRS Labs SR530, Lock-In Amplifier manual Output Channel, Rel Channel, Offset Channel

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display

CH1

 

 

X

setting

output expand? offset?

(RCOSØ)

X

X+Xofst

yes

yes

X+Xofst

XOFST

Xofst

yes

yes

Xofst

R

R+Rofst

yes

yes

X+Xofst

R OFST

Rofst

yes

yes

X+Xofst

XNOISE

X noise

yes

yes

X+Xofst(enbw)

X5

X5

no

adjust

X+Xofst

The EXPAND and OFFSET conditions for each display are retained when the DISPLAY is changed. Thus, when the DISPLAY is changed from X to R, the EXPAND and OFFSET assume the conditions set the last time the DISPLAY was R. If the DISPLAY is changed back to X, the EXPAND and OFFSET return to conditions set for X.

R Output

The magnitude, R, is given by the equation:

R = {(X+Xofst)2 + (Y+Yofst)2}1/2 + Rofst

Note that the X and Y offsets affect the value of R while the X and Y expands do not.

The magnitude output has a resolution of 12 bits plus sign and is updated every 3.5 mS. To achieve maximum accuracy, the magnitude should be as large a fraction of full scale as possible.

R is expanded after the calculation. Thus, when R is expanded, the full scale resolution drops by a factor of 10 to about 9 bits.

Output Channel 1

The CHANNEL 1 output is available at the left hand OUTPUT BNC connector. The output parameter is selected by the DISPLAY setting and can be X, X OFST, R (magnitude), R OFST, X NOISE, or X5 (external D/A). (Note that X5 is the ratio output at power up. When displaying X5, the ratio output is 10R/X1). All outputs are ±10V full scale when the EXPAND is off. With the EXPAND on, the output is multipled by 10 effectively increasing the full scale sensitivity by 10. (X5 may not be expanded). The output impedance is < 1Ω and the output current is limited to 20 mA.

The left hand analog meter always displays the CHANNEL 1 OUTPUT voltage. Accuracy is 2% of full scale.

The CHANNEL 1 LCD display provides a read-out of the displayed parameter in real units. The scale of the displayed quantity is indicated by the three scale LED's to the left of the display. This read- out auto ranges and will reflect the sensitivity added when the EXPAND function is on. When displaying X5, the scale LED's are off and the units are volts.

Rel Channel 1

Every time the REL key is pressed, the displayed parameter is offset to zero. This is done by loading the displayed parameter's offset with minus one times the present output. If the output is greater than 1.024 times full scale, the REL function will not be able to zero the output. In this case, the OFFSET ON LED will blink and the offset value will be set to its maximum value.

The REL function and the manual OFFSET are both ways to enter the offset value. After using the REL key, the offset may be adjusted using the manual OFFSET.

When the DISPLAY is X, X OFST, or X NOISE, the REL key sets the X OFFSET (which affects the X (RCOSØ) output). If X NOISE is being displayed, the REL function zeroes X and the noise output will require a few seconds to settle again.

When the DISPLAY is R or R OFST, the REL key sets the R OFFSET.

The REL key zeroes the X5 output when the DISPLAY is D/A.

Offset Channel 1

The OFFSET buttons control the manual offset. The offset is turned ON and OFF using the upper key in the OFFSET section. When the offset is ON, the lower two keys are used to set the amount of offset. A single key press will advance the offset by 0.025% of full scale. If the key is held down, the offset advances in larger and larger increments, the largest increment being 10% of full scale. When the offset is turned OFF the applied offset returns to zero but the offset value is not lost. The next press of the upper offset key (return

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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 ChannelExpand Channel Rcosø OutputChannel 2 Display Auto Phase Rsinø Output Reference InputTrigger Level Time Constant Reference ModePhase Controls Reference DisplayPower DefaultsLocal and Remote 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 Errors Status ByteBit Common Software Problems include ResetTrouble-Shooting Interface Problems Common Hardware Problems includeSR530 with the Gpib Interface SR530 with the RS232 InterfaceSerial Polls and Service Requests Gpib with RS232 Echo ModeSR530 with Both Interfaces 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 PanelPower Supplies RS232 InterfaceGpib Interface Multiplier Adjustments Amplifier and Filter AdjustmentsCalibration and Repair 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 ShieldedCY1 FU1MPSA18 SR530 Component Parts List SR530 Component Parts List SR530 Component Parts List SR530 Component Parts List SR530 Component Parts List SPSTX8 4PDTSR513 Assy SR530 Component Parts List Static RAM, I.C Z80A-CPU#4 Flat TIE AnchorTranscover MicaFront Panel Board Parts List RED LD1 LD2LD3 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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