In-situ RDO Blue Operator's Manual page 23

Gently dry the probe and sensing element with a
paper towel.
Be sure the sensor surface is dry when you place the probe into the calibration chamber.
Two-Point Calibration or Concentration-Based Calibration
Remove the water-saturated sponge from the
calibration chamber. Fill the chamber to the fill line
with approximately 60 mL of fresh sodium sulfite or
another solution.
1-970-498-1500
Place the probe in the calibration chamber so that
the sensing element is about 2.5 cm (1 inch) above
the water-saturated sponge.
Place the probe into the solution. Leave at least
13 mm (0.5") between the surface of the sensing
element and the bottom of the chamber.
23 www.in-situ.com