I am looking for an X-rite blue/green sensitometer to compare with the Wejex and the EG&G. I am starting to beleive that these relatively small battery operated, LED driven devices may have some advantages for B&W testing. The main drawbacks are that I think the exposure time is long (like a second or so, like the Wejex) but I am not shure. The on line PDF file for the 393/394 indicates that there are 7 different exposure settings but does not list the times in the specs.
I even refreshed my memory on reciprocity by looking back at the Zakia and Todd book on Sensitometry and I still think that when one is just interested in "process control" information (specifically DEVELOPMENT TIME), the duration of exposure in the sensitometer does not make much difference.