CHAPTER 8 COMPONENTS OF THE MINI-PAM
8.4 Micro Quantum/Temp.-Sensor 2060-M
The Micro Quantum/Temp.-Sensor 2060-M essentially displays
the same features as outlined above for the Leaf-Clip Holder 2030-B
(see 8.3), except that the micro-sensors of PAR and temperature are
not mounted in a leaf-clip. This device is rather designed for
experiments with objects which are not leaf-shaped, like crustose
lichens and cushions of moss. The two miniature sensors can be
attached to the site where fluorescence is monitored without
interfering with the actual measurement. A defined position with
respect to the object and the fiberoptics exit plane can be achieved
with the help of a special holder, in analogy to the 'Distance Clip'
(shown in Fig. 5).
It should be pointed out that the sensitivity of the micro quantum
sensor is affected by bending the relatively long, flexible light guide
which bridges the distance between the small diffusing disk at the
object and the detector in the metal housing. Therefore, this device
cannot substitute for a reliable quantum sensor like the LI-COR
Quantum Sensor (Type LI-190), against which it was originally
calibrated. Recalibration via menu points 40 and 41 is recommended
when bringing the sensor and the metal housing into a fixed position
with respect to the object.
8.5 External Halogen Lamp 2050-HB
The External Halogen Lamp 2050-HB provides a strong light
source for prolonged illumination periods, for which purpose the
internal halogen lamp is not suited because of the heat developing
within the MINI-PAM housing. A 20 W lamp is powered by an
external battery (e. g. NP-3/12). Its intensity can be varied steplessly
via a 15-turn potentiometer. Power consumption is minimized by
special electronic circuitry. The lamp is equipped with a heat-
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