We used a sound card instead of an A/D card for interfacing a spectrophotometer with a personal computer (PC) via a microphone port. The output signal of the spectrophotometer was simply converted to an oscillating signal by using a small voltage-controlled oscillator (VCO), and then sent to a PC via a microphone port.
(1) Amornthammarong, M.; Jareonsutasinee, K.; Nacapricha, D. LRA. 1999, 12, 138-141. Click here to download.