The MICROFIBER-PAM employs a very thin optical fibre for fluorescence excitation and detection. This narrow fibre permits probing of small spots of heterogeneous photosynthetic surfaces like soil crusts. Placing the microfiber at different penetration depths permits measurements of photosynthetic gradients within microbial mats and leaves.
The central part of the MICROFIBER-PAM is a fibre optic coupler consisting of a beam splitter to which two pairs of fibres are connected. This four port coupler distributes light incoming from one fibre pair to the other pair, where each fibre pair can function as input.
Typically, the fibre optic coupler conducts emission from an LED to the sample, and guides fluorescence from the sample back to a highly sensitive photomultiplier which is shielded against LED light by glass filters.
Both light emission of the LED and fluorescence measurement by the photomultiplier are coordinated by the PAM-CONTROL unit.
The PAM-CONTROL unit allows stand-alone operation of the MICROFIBER-PAM but functions also as a physical interface for computer-controlled operation of the MICROFIBER-PAM.
Fibre optic coupler consisting of a central beam splitter (black elongated central part) and four multi-mode optical fibres (orange cable) with ST (straight tip) connectors. Grey box: Photomultiplier.
Normally, the MICROFIBER-PAM uses blue LED light for fluorescence excitation but alternative LEDs emitting in the green and red spectral range are available.
Peak emission of the blue LED is 470 nm. The LED emits pulses of several µs duration to elicit the pulse-modulated fluorescence measured by the MICROFIBER-PAM, but also longer-lasting pulses which produce integrated light intensities which can saturate photosynthesis.
Universal Control Unit PAM-CONTROLFor control of Photomultiplier-detector PM-MF and LED |
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General Features |
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Data memory: | 128 kB CMOS RAM providing memory for 4000 data sets |
Microcontroller: | CMOS 80C52 |
Display: | 2 x 24 character alphanumerical LCD with backlight |
User interface: | 2 x 4 touch-sensitive keys to operate the internal mode menu |
Measured parameters: | Fo, Fm, Fm’, F, Fv/Fm (max. Yield), ΔF/Fm’ (Yield), qP, qN, NPQ, PAR (using special micro quantum sensor), ETR (i.e. PAR x ΔF/Fm’) |
General Design |
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Power supply: | Internal rechargeable battery 12 V/2 Ah, providing power for at least 10 000 Yield measurements, automatic power/off, battery charger MINI-PAM/L (100 to 240 V AC) |
Dimensions: | 17.6 cm x 11.5 cm x 9.5 cm (L x W x H) |
Weight: | 2 kg (incl. battery) |
Operating temperature: | -5 to +45°C |
Connectors |
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Actinic light: | Drives up to three actinic LEDs |
AUX input: | Receives signals from temperature and light sensors |
AUX output: | Sends control signals for external LED drivers |
Charge: | Socket for battery charger |
Far red light: | Up to three far red LEDs can be driven |
Measuring light: | Capacity to drive up to three LEDs both as measuring and actinic light sources, 12 LED intensity and 12 pulse frequency settings are available, automatic change of measuring light frequency. |
Output: | Provides analogue signal to chart recorder |
Photomultiplier: | Full control of photomultiplier PM-MF |
RS232: | Data transfer to computer using WinControl V. 2 software |
Computer-controlled Operation |
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Software: | WinControl-2 (Windows 3.1x/9x/Me/NT4/2000/XP). WinControl-3 (Windows XP/Vista, Windows 8). |
Battery Charger MINI-PAM/L |
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Input: | 100 to 240 V AC, 47 to 63 Hz |
Output: | 19 V DC, 3.7 A |
Operating temperature: | 0 to 40°C |
Dimensions: | 15 cm x 6 cm x 3 cm (L x W x H) |
Weight: | 300 g |
Analogue output cable for a chart recorder PAM-2000/K1 |
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Length: | 1.5 m |
Weight: | 70 g |
USB-RS 232 adapter and RS 232 cable PAM-2000/K3 | Variable specifications, depending on market offers |
Transport Box CONTROL-T |
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Design: | Aluminium box with custom foam packing for PAM-CONTROL and accessories |
Dimensions: | 60 cm x 40 cm x 25 cm (L x W x H) |
Weight: | 5 kg |
Four Port Fibre Coupler MF-2-2-100 |
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Design: | 100/140 μm (core/cladding diameters) step index fibres, 2 input and 2 output arms with ca. 1.2 m lengths and ST-connectors at all ends, PVC-adapter to connect photomultiplier PM-MF |
Weight: | 85 g |
Photomultiplier PM-MF |
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Design: | Based on photosensor module H-6779-01 (Hamamatsu) with pulse preamplifier and automatic overload switch-off, aluminium housing with mounting rod to be fixed on Stand ST-101 |
Signal detection: | Miniature photomultiplier with high red sensitivity (type H6779-01, Hamamatsu) |
Dimensions: | 110 mm x 65 mm x 78 mm (H x W x D) |
Weight: | 520 g (incl. 1.4 m cable) |
Blue LED MF-L470 |
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Emission peak: | 470 nm |
Short-pass filter: | λ < 600 nm |
Detector-filterset: | λ > 640 nm |
Dimensions: | Ø 25 mm, length 112 mm |
Weight: | 115 g (incl. 1.4 m cable) |
Adapter Set MF-A |
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Design: | Consisting of filter holder, which mounts on Photomultiplier-Detector PM-MF, with adapter for fibre coupler MF-2-2-100, and a holder for mounting up to four LED light sources for the MICROFIBER-PAM, to be fixed on stand ST-101 |
Stand with Base Plate ST-101 |
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Dimensions: | Base plate, 39.5 cm x 30 cm. |
Height: | 76.5 cm, diameter 1.5 cm |
Weight: | 2.8 kg |
Accessories |
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Green LED MF-L520 |
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Emission peak: | 520 nm |
Short-pass filter: | λ < 600 nm |
Detector-filterset: | λ > 640 nm |
Dimensions: | Ø 25 mm, length 112 mm |
Weight: | 115 g (incl. 1.4 m cable) |
Red (630 nm) LED MF-L630 |
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Emission peak: | 630 nm |
Short-pass filter: | λ < 680 nm |
Detector-filterset: | λ > 710 nm |
Dimensions and weight: | Green LED MF L470 |
Red (650 nm) LED MF-L650 |
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Emission peak: | 650 nm |
Short-pass filter: | λ < 680 nm |
Detector-filterset: | λ > 710 nm |
Dimensions and weight: | Green LED MF L470 |
Working Fibre MF-F |
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Design: | Single 100/140 μm step index fibre with ST-connector on one end and free fibre on other end, including connector to link with Multimode Fibre coupler MF-2-2-100 |
Total length: | 2 m |