SpectraPen SP 110 Photon Systems Instruments Categories Crops , Photosynthesis, Chlorophyll & Respiration Brochure Send Enquiry Overview PSI SpectraPen SP 100 a handheld, programmable spectrophotometer that provides instant readings and spectral lines on interactive touch screen. Applications include visible light source testing, color measurement and chemical measurement. Back Our Related Products Qubit Systems Gas Flowmeters Learn More Photon Systems Instruments PSI Thermoregulator TR 2000 Learn More Photon Systems Instruments Thermoluminescence System TL 500/LT Learn More Soil Moisture Specimen Holder Learn More