As field engineers, during our communication with university researchers and users, we often encounter the following high-frequency questions:
• Why does the product yield fluctuate even when the experimental conditions remain constant?
• Why can’t we reproduce the same optical parameters even when using the exact same light source as described in the literature?
• Why do reaction rates differ between light sources under identical light power density?
Excluding variables from the reaction setup itself, the stability of the light source is often the core issue. Researchers all wish to obtain a “perfect beam of light” to eliminate experimental errors, but the reality is—a truly perfect light source does not exist. Photocatalysis and photochemical reactions are fundamentally photon-driven chemical processes. Although we cannot achieve an absolutely constant light output, we can modify and control the light through technical means to acquire accurate and reliable data.
Most commercial xenon lamp sources on the market are variations of the XXX300 series, and they essentially use the same core bulb ↓↓
Since the emission core is identical, the optical parameters should theoretically be similar. So where does the difference come from?
The key lies in two critical factors: light power density and spectral energy distribution. The emission mechanism of xenon lamps is straightforward: besides the characteristic 820–1000 nm spectral lines from xenon electronic transitions, most output originates from the high-temperature, high-pressure xenon plasma arc formed between the electrodes.
This plasma is extremely hot—hot enough to slowly ionize and erode the cathode tip. After extended operation, electrode wear changes the arc gap, leading to fluctuations in light power density.
Conclusion: Light power attenuation in xenon lamps is an unavoidable physical property, and the decay is fastest in the early stage of a new bulb.
Many users only pay attention to whether the lamp is “bright or not,” while ignoring current readings and light intensity decay. Neglecting these core variables is the true reason behind “irreproducible results in repeated experiments.”
The attenuation of xenon lamp power cannot be reversed or completely avoided, but the loss can be compensated through proper technical measures.
Traditional suggestion: Set the working current of a new lamp at about one-third of the rated range. As the light output decreases, gradually increase the current to compensate for the loss.
The challenge: The relationship between current and light power density is not strictly linear, and individual differences between lamp units make it impossible to use a universal formula for precise compensation.
Common misconception: “Using a standard photocatalyst to calibrate light power.”
In theory, this works. In practice, however, it requires absolute consistency in solution batches, catalyst activity, and all other variables—dramatically increasing experimental time cost and contradicting the scientific pursuit of “efficiency and accuracy.”
To solve light power calibration and ensure long-term stability in extended experiments, these two devices are essential:
No.1 The ‘ruler’ of experimental data: PL-MW2000 High-Intensity Optical Power Meter
Photocatalytic experiments cannot be performed reliably without a power meter; otherwise, catalyst modification data and repeatability studies can easily become distorted.
The classic PL-MW2000 High-Intensity Optical Power Meter helps researchers shift from vague “perceived brightness” to precise “quantitative control,” ensuring the reliability of scientific conclusions.
No.2 The ‘stabilizer’ for long-duration experiments: Microsolar300 Xenon Light Source
If your research involves tens or hundreds of hours of long-period or fatigue testing, a power meter alone is insufficient—manual calibration not only interrupts experiments but can introduce new errors such as light spot displacement.
The core advantage of the Microsolar300 xenon lamp is this: it integrates an optical feedback module directly in the light path, allowing real-time monitoring of light intensity without disturbing the beam spot. Through chip-based automatic regulation, it ensures stable output over long durations and eliminates the complications caused by power decay. For more details, call 400-1161-365.
Once you understand the variation pattern of light power density—and equip yourself with the right tools—you’ve already taken a solid step toward achieving PerfectLight.
