How to measure absorbance at 882 nm? I am trying to measure the absorbance of a solution at 882 nm, but this seems to be beyond the range of many UV-Vis spectrometers. Is this a job for the IR spectroscopy, or something else? I do not have much experience with IR spectroscopy.
No this is not a job for an IR machine. It all depends on the machine you are using, but provided the monochromators will extend that far all that may be necessary is to change the detector for one that is more red sensitive. If your machine will not do the job, and if its a one-off type of measurement  try to get time on another machine somewhere else. If this is not possible or you need to measure many samples over a long period you may need to experiment by using a lamp , interference filters and a detector etc and make your own machine to measure transmittance.