Measuring thermoluminescence is a powerful tool used in the study of photosynthesis. The Z700 Thermoluminescence System is designed to investigate the structure of energetic levels in the Photosystem II. Light-induced charge separation in the Photosystem II reaction centers results in accumulation of radical pairs that store the absorbed light energy. Heating induces recombination of these radical pairs and it triggers light emission and formation of characteristic thermoluminescence glow curves in the temperature range of 0-60°C. The shape and the peak position of the different thermoluminescence bands provide valuable information about the energetic stability of the respective radical pair as well as about the functioning of the Photosystem II reaction centers.
The Z700Thermoluminescence System is used for measuring thermoluminescence and also for detecting and measuring delayed luminescence signal.
The Thermoluminescence System consists of three major parts:
The Multipurpose Control Unit executes experiments according to protocols defined by users or according to the Thermoluminescence Wizard protocols. There are two Channel inputs in the Unit. One serves for measuring thermoluminescence signal (TL Signal) and the other serves for measuring temperature. Measured curves are displayed in two formats: Time/Temperature and Time/TL Signal, or Temperature/TL Signal.
The Thermoregulator Control Unit can control the temperature of a sample in the range of -25°C to +70°C with an accuracy of 0.1°C. The actual temperature is displayed on the front panel of the device. The temperature can be regulated either manually or it can be controlled by a protocol. The Unit can work in two modes - constant mode and temperature ramp mode. In the constant mode, the instrument maintains a constant temperature of the measured sample. The temperature ramp mode enables linear changing of the sample temperature with a rate ranging from 0.1°C/sec to 2°C/sec.
The Measuring Chamber consists of four key parts:
Light Source
Photomultiplier
A/D Converter
Sample Disc with Temperature Controller
Light Source
The light source is formed by eight super-bright Lumileds (max=630 nm) that can emit flashes of up to 200,000 µmol photons m-2 s-1. The maximum flash duration is 150 µs. Light intensity and flash duration are software controlled.
Photomultiplier
The photomultiplier detects photons in the range of 300 to 900 nm. This enables measurement of thermoluminescence signal and of delayed fluorescence as well. The photomultiplier also includes its own Power Supply.
A/D Converter
The electric current of the photomultiplier is amplified with software-controlled gain and digitized. The time response of the amplifier is fixed at 50 ms determining the minimal sampling period to 100 ms.
Sample Disc with Temperature Controller
The sample holder is a disc (1/2 inch in diameter) made of gold-plated copper. The typical sample is a suspension of cells, chloroplasts or membranes. Leaves 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 -25°C to +70°C with an 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.
Producing Area:Canada