Spectrometer
Spectrometer is a device module in SweepMe!. It measures optical spectra and spectral properties of light sources and samples.
Overview
The Spectrometer module captures optical spectra across ultraviolet to infrared wavelengths. It provides flexible integration time control, averaging, referencing, and post-processing including peak detection and CIE color analysis. The module supports automated background and reference measurements with optional saturation compensation. Available drivers can be found at sweep-me.net/devices. Sweep modes are driver-specific and may include wavelength, grating selection, or temperature sweeps.
GUI parameters
Integration Time
Detector exposure time per spectrum in milliseconds. Longer integration increases signal and signal-to-noise ratio but requires longer measurement time. Typical range: 1–10000 ms.
Driver parameter key: IntegrationTime
Automatic Integration Time
When enabled, the spectrometer automatically adjusts integration time to prevent saturation while maintaining adequate signal level. Uses saturation minimum and maximum thresholds.
Driver parameter key: IntegrationTimeAutomatic
Saturation Minimum
Lower threshold (percentage of max detector output) for automatic integration adjustment. Prevents measurements from being too dark. Typical: 20%.
Driver parameter key: SaturationMinimum
Saturation Maximum
Upper threshold (percentage of max detector output) for automatic integration adjustment. Prevents detector saturation and blooming. Typical: 90%.
Driver parameter key: SaturationMaximum
Filter
Optical filter selection (if multi-filter instrument). Common options: UV, Visible, IR, or Neutral Density (ND) filters.
Driver parameter key: Filter
Average
Number of spectra to average at each measurement point. More averages reduce noise but increase measurement time.
Driver parameter key: Average
Shutter
External shutter control (if supported). Options: Open, Closed, Auto.
Driver parameter key: Shutter
Trigger
External trigger mode for synchronization with other instruments:
- Internal – No external trigger
- External – Waits for external trigger signal before measurement
- Software – Triggered by measurement sequencer
Driver parameter key: Trigger
Trigger Delay
Delay in seconds after trigger signal before acquisition begins.
Driver parameter key: TriggerDelay
Trigger Timeout
Maximum time in seconds to wait for external trigger. If exceeded, acquisition proceeds without trigger.
Driver parameter key: TriggerTimeout
Reference Start
Acquires a reference spectrum at the beginning of the measurement. Used as baseline for relative measurements or post-processing.
Driver parameter key: ReferenceStart
Reference File
Path to a reference spectrum file for flat-field or responsivity correction. Required for absolute spectral measurements.
Driver parameter key: ReferenceFile
Post-processing
Enable post-processing calculations on acquired spectra:
- Peak wavelength – Wavelength of maximum intensity
- Total intensity – Integrated spectral power (area under curve)
- CIE 1931 coordinates – X, Y, Z color matching functions for human-visible light
Driver parameter key: PostProcessing
Variables
| Variable | Unit | Description |
|---|---|---|
| Wavelength | nm | Wavelength axis of spectrum |
| Intensity | counts or W/m²/nm | Spectral radiance (counts or calibrated units depending on reference) |
| Peak wavelength | nm | Wavelength of maximum intensity (post-processing) |
| Total intensity | W or counts | Integrated intensity across spectrum (post-processing) |
| CIE X | — | CIE 1931 color matching X coordinate (post-processing) |
| CIE Y | — | CIE 1931 color matching Y coordinate (post-processing) |
| CIE Z | — | CIE 1931 color matching Z coordinate (post-processing) |
Usage
- Select a spectrometer driver and configure port/channel.
- Set integration time — lower for bright sources, higher for dim sources.
- Configure averaging for noise reduction if needed.
- Select the optical filter appropriate for the measurement range.
- Optionally enable automatic integration time with saturation thresholds.
- For referenced measurements, acquire a reference spectrum at the start.
- Enable post-processing (peak detection, color analysis) as needed.
- Verify that the spectral range and responsivity match the measurement requirement.
Applications
- LED characterization – Color point, spectral distribution, luminous intensity
- Solar cell spectral response – External quantum efficiency (EQE) measurements
- Light source characterization – Color temperature, CRI, spectral content
- Optical filter verification – Transmission wavelength verification
- Emission spectroscopy – Atomic/molecular emission line identification
- Absorption spectroscopy – Sample transmission and reflectance characterization
- Fluorescence measurement – Fluorophore excitation and emission spectra
- Colorimetry – Color matching, CIE coordinate determination
See also
- LCRmeter – Complementary impedance-based characterization
- Monochromator – Wavelength selection for spectral response measurements
- Camera – Spatial resolution of optical properties