Meter displays dissolved oxygen (DO) readings in mg/L, ppm, or % saturation with simultaneous temperature display. Independent 100% and 0% calibration points provide high accuracy over the entire range. Increase reading accuracy by entering barometric pressure and salinity — meters automatically calculate offset.


Electrode diagnostics are easily completed with the electrode slope, zero offset, and millivolt display options. Download data via optional RS-232 cable (order separately below).

Meter 35640-20 come with 10-ft galvanic DO probe 35640-50.