Luminescence Routine Commands

This section lists the commands specific to the Luminescence routine.

Settings JSON

{"integration_time":100,"averages":1,"pixel_smoothing":1}

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Data JSON

{
  "wavelengths":[336.2,336.8,337.4,337.99,338.59,...],
  "dark":[98.15,96.57,100.65,97.65,98.65,...],
  "reference":[1.74,4.32,0.99,1.32,-4.26,...],
  "spectrum":[-3.56,-0.64,-0.39,-1.14,-4.72,...],
  "irradiance":[-5.34374988703235E-10,-9.68753827157443E-11,-0.0404323935508728,-1.71875375043484E-10,-7.09375724827765E-10,...],
  "absorbance":[NaN,NaN,NaN,NaN,-0.0444840553995501,...],
  "transmittance":[-2.05776536017416,-0.149686749033192,-0.403400873932853,-0.871634601433505,1.10785789095536,...]
}

invalid data

All fields are always send, even if the array is empty. This may happen if no reference is taken, in that case, the absorbance and transmittance fields will contain an empty array.

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Custom Commands

Command	Description
AcquireDark / AcquireReference	Capture a reference spectrum.
AcquireSingle	Capture a spectrum.
AutoExposure	Automatically determine optimal integration time.
SetLaser	Enable or disable the excitation laser.

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AcquireDark / AcquireReference

Description
Captures a spectrum and stores it in memory either as Dark / Reference. The current spectrometer settings are used. Returns a 2D array with 2 rows: Wavelength in nm and raw spectrum

Warning

A new dark/reference must be acquired each time the integration time changes

Example Request

{
  "target": "ROUTINE",
  "command": "AcquireDark",
  "request_id": 201
}

Example Response

{
  "status": "OK",
  "data": { 
    "spectrum": [[144.6012,145.207,145.8128, ...],  //wavelength in nm
                 [80.49375,93.57708,102.1604, ...]] //spectrum in a.u.
    },
  "request_id": 201
}

---

AcquireSingle

Description
Captures a spectrum. Returns a 2D array with 3 rows: Wavelength in nm, raw spectrum, irradiance in µW/cm².

Info

The 2nd row is the raw spectrum of the spectrometer and does not include the dark subtraction.

Info

Irradiance is only valid when a dark spectrum is acquired before this function is called.

Example Request

{
  "target": "ROUTINE",
  "command": "AcquireSingle",
  "request_id": 201
}

Example Response

{
  "status": "OK",
  "data": { 
    "spectrum": [[144.6012,145.207,145.8128, ...],  //wavelength in nm
                 [80.49375,93.57708,102.1604, ...], //spectrum in a.u.
                 [0.24535,0.2544,0.34538, ...]]     //irradiance in µW/cm²
    },
  "request_id": 201
}

---

AutoExposure

Description
Determines the optimal integration time for luminescence acquisition by iteratively measuring signal intensity. The result includes the selected exposure time in milliseconds.

Example Request

{
  "target": "ROUTINE",
  "command": "AutoExposure",
  "parameter": { },
  "request_id": 203
}

Example Response

{
  "status": "OK",
  "data": {"integration_time":50, "averages":5},
  "request_id": 203
}

---

SetLaser

Description
Controls the excitation laser used during luminescence measurements. Set the PWM frequency and duty cycle of the selected laser channel.

Example Request

{
  "target": "ROUTINE",
  "command": "SetLaser",
  "parameter": {"channel":0, "frequency":10000, "duty_cycle":50, "intensity":50},
  "request_id": 204
}

duty cycle vs intensity

The SetLaser command accepts duty_cycle or intensity to set the intensity of the light. Some light work in opposite amplitude, i.e. a duty cycle of 0% corresponds to 100% intensity. Other light may saturate at 50% duty cycle. In that case, the 0-100% intensity is mapped to a duty cycle of 0-50%. It is recommended to use intensity to set the actual light intensity. While duty_cycle remains available for testing.

Example Response

{
  "status": "OK",
  "data": { "state":"OK" },
  "request_id": 204
}

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Example Command Sequence

Note

For the following examples, it is assumed that a light source is attached to the spectrometer at channel 0.

PL measurement

{ "target": "MAIN",    "command": "StartRoutine", "parameter": { "routine": "Luminescence"} }
{ "target": "ROUTINE", "command": "GetTestStatus" } // repeat until routine_status == "Ready"
{ "target": "ROUTINE", "command": "SetLaser", "parameter": { "channel":0, "duty_cycle":100 } }
{ "target": "ROUTINE", "command": "AutoExposure" }
{ "target": "ROUTINE", "command": "AcquireSingle" }
{ "target": "ROUTINE", "command": "SetLaser", "parameter": { "channel":0, "duty_cycle":0 } }
{ "target": "ROUTINE", "command": "AcquireDark" }
{ "target": "ROUTINE", "command": "GetTestData" } 
{ "target": "ROUTINE", "command": "CloseRoutine" }

Transmittance/Absorbance measurement

{ "target": "MAIN",    "command": "StartRoutine", "parameter": { "routine": "Luminescence"} }
{ "target": "ROUTINE", "command": "GetTestStatus" } // repeat until routine_status == "Ready"

//Place Reference Device

{ "target": "ROUTINE", "command": "SetLaser", "parameter": { "channel":0, "duty_cycle":100 } }
{ "target": "ROUTINE", "command": "AutoExposure" }
{ "target": "ROUTINE", "command": "AcquireReference" }
{ "target": "ROUTINE", "command": "SetLaser", "parameter": { "channel":0, "duty_cycle":0 } }
{ "target": "ROUTINE", "command": "AcquireDark" }

// Place Device

{ "target": "ROUTINE", "command": "SetLaser", "parameter": { "channel":0, "duty_cycle":100 } }
{ "target": "ROUTINE", "command": "AcquireSingle" }
{ "target": "ROUTINE", "command": "GetTestData" } 
{ "target": "ROUTINE", "command": "CloseRoutine" }

Transmittance Calculation

Transmittance = Spectrum / Reference

Absorbance = -log10(Transmittance)

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