Measuring Chamber
The Measuring Chamber consists of four key parts:
1. Light Source
2. Photomultiplier
3. A/D Converter
4. Sample Disc
1. Light Source
Installed LEDs (λmax=625 nm) offer single turnover flashes focused on 1/2" sample pan. Flash duration and intensity can be defined in protocols. Appropriate light signals are controlled by the Fluorometer Control Unit.
For Standard and High-Temperature versions, the maximum intensity of a single turnover flash is around 200,000 µmol(photons).m-2.s-1. Maximum flash duration is 150 µs.
For Liquid Nitrogen version, the maximum intensity of a single turnover flash is around 130,000 µmol(photons).m-2.s-1; maximum intensity of actinic light is around 300 µmol(photons).m-2.s-1 .
2. Photomultiplier
The photomultiplier detects photons in the range of 300 to 900 nm. This enables detection of both the thermoluminescence signal and optically stimulated delayed luminescence as well.
Photomultiplier Control Panel
3. A/D Converter
The electric current of the photomultiplier is amplified with software-controlled gain. The time response of the amplifier is fixed at 50 ms determining the minimal sampling period to 100 ms. The signal is then digitalized in the Measuring Chamber.
4. Sample Disc
The sample disc (1/2 inch in diameter) is made of gold-plated copper. The typical sample is a suspension of cells, chloroplasts or membranes. Leave segments can be also measured when a small amount of water is added to them. The temperature sensor, which is situated right under the sample holder, is calibrated in the range of -90°C to +200°C with an absolute accuracy of ±0.1°C. The sample holder is cooled and heated by the built-in Peltier cell. For temperatures lower than +10°C an outer cooling water-circuit is required. For temperatures below -25°C, an additional Liquid Nitrogen Unit must be used.
Gold-Plated Copper Sample Disc
Fluorometer FL 3500 Control Unit
Thermoregulator TR 2000
Additional Cooling or Heating Units
