Dosimetry™

Quantitation of light delivery.
Stable, solid-state light, titrated precisely.

Lumencor light engines are uniquely well suited for quantitative fluorescence analysis. Light outputs may be read as photon counts which are proportional to photon number, not intensity or power. Pulse to pulse reproducibility is excellent: standard deviations typically less than 0.1%. The thermalized light engine output increases linearly in time or pulse width. All the light delivered can be monitored in real time and measured electronically. This capacity to titrate photon number in a given experiment provides an unprecedented level of precision and therefore experimental control of light similar to measuring reagents in a chemical reaction. Light engine outputs can be controlled by a variety of means. To overcome the influence of environmental changes and any light engine performance variation on the optical output, three closed loop options exist to stabilize photon delivery:

 

  • Constant current
  • Metered dosage
  • Constant intensity

These closed loop options are important for controlling inter-assay reproducibility but also for monitoring inter-instrument reproducibility. Metered dosage offers the most control in that the actual number of photons is known, impervious to temperature fluctuations and thus extremely reproducible. Using metered dosage OEMs can calibrate all their light engines for all instrument products to deliver the same output power at a particular setting.

constantcurrent

Constant Current

Available today. The light engine circuitry monitors the current through each source and keeps it constant. Once thermalized, the power output is constant for constant ambient temperature and pressure and the pulse to pulse reproducibility is better than 99%. Performance bests the arc lamps but light engine outputs can be influenced by a function of warm up, duty cycle, power and atmospheric conditions.

meter

Metered Dosage

Offered today to OEMs willing to adopt metering electronics into their light engines. Here a portion of the light engine output beam, internal to the light engine, is monitored. When the light engine’s internal counter reaches a desired dosage, the light is turned off. The output is locked into the photon number and dosage is not susceptible to atmospheric influences.

constantintensity

Constant Intensity

Offered today to OEMs willing to adopt constant intensity electronics into their light engine. Broad release in 2014. To maintain the same power per unit time, Lumencor employs a circuit that monitors the light and adjusts intensity in real time. This is most applicable for rolling shutter camera applications.