BLUE & AMBER Version
Measuring Heads MICRO‑HEAD/3B and MICRO‑HEAD/3A

MICRO-PAM systems can be configured with measuring heads MICRO-HEAD/3B and MICRO-HEAD/3A. The measuring head MICRO-HEAD/3B probes photosynthesis with blue light which has a peak intensity at 460 nm and full width at half maximum of 27 nm (Fig. 1). MICRO-PAM and MONI-PAM systems employing blue light have successively proven itself in terrestrial and aquatic research.

The measuring head MICRO-HEAD/3A possesses an amber LED with emission peaking at 598 nm and a full width at half maximum of 22 nm (Fig. 1). Amber light is better absorbed by cyanobacteria than blue light. Correspondingly, the quality of the PAM signal excited by amber light is superior to that excited by blue light. For this reason, MICRO-PAM systems configured with measuring heads MICRO-HEAD/3A are particularly suited to probe cyanobacterial mats and lichens, or crusts containing cyanobacteria.

BLUE and AMBER Versions are further distinguished by the spectral window for fluorescence detection. The BLUE version detects fluorescence at wavelengths > 600 nm, whereas the AMBER version detects fluorescence at wavelengths > 700 nm (Fig. 2).