My ZoneVI Compensating Development Timer is in desperate need of repair/recalibration/adjustment, and I wondered if anyone knows if this is even possible?
After seeing that recently developed film was significantly under-developed, I decided to check the compensating aspects of the timer. I placed the ZoneVI probe in a beaker of water measured at 68F using a Kodak thermometer, and compared the ZoneVI times with a stop watch. My assumption is that at 68F, the compensated time and real time should be the same, or very close. Instead I found that while the ZoneVI "real time" setting agrees with my stop watch, the "film" and "paper" settings are about 50% off, so that when the ZoneVI timer says, for example, that 4:30 has elapsed, the stop-watch elapsed time is only 3:00; if anything the error is slightly worse on the "paper" setting, almost a 60% difference.
My sense is that either there is a problem with the circuitry in the timer, or something has failed in the temperature probe. Any suggestions would be greatly appreciated, especially if the old "ZoneVI hands," Mssrs. Barlow and Ritter have any thoughts.
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