In-situ RDO PRO-X, Operator'S Manual, Page: 9 / 29

9
Calibrate the RDO PRO-X Probe
Calibrate the sensor with Win-Situ 5 software or the VuSitu mobile app, or calibrate directly with your controller.
1-Point Calibration
The optical Rugged Dissolved Oxygen sensor is very stable. The factory calibration should produce readings within 3%
accuracy. If you require readings with greater accuracy we recommend that you perform a 1-point, 100% water-saturated air
calibration as described below.
Water-Saturated Air
1. Remove the storage cap from the top of the calibration chamber and replace it with the vented calibration cap.
1 Storage cap
2 Vented calibration cap
Figure 6.1 Storage cap and vented calibration cap shown together
2. Place the sponge wafer in the bottom of the calibration chamber and saturate with approximately 10 mL water.
3. Gently dry the instrument and sensing material with a paper towel, making sure there is no water or debris on the
instrument or on the sensing surface.
4. Place the instrument into the calibration chamber about 2.5 cm (1 in.) above the water-saturated sponge.
Figure 6.2 Calibration chamber with water-saturated sponge
5. Allow 5 to 10 minutes for temperature stabilization prior to starting the calibration procedure. Do not leave the
instrument in the calibration chamber for more than 30 minutes. This can allow condensation to form on the
sensing material, which will produce false low readings after calibration. If condensation does occur, remove the
instrument, dry the sensing material, place the instrument in the chamber, and calibrate.
2-Point Calibration
100% and 0% Saturation
We recommend that you perform the 0 % oxygen calibration only if you intend to measure dissolved oxygen at a
concentration of less than 4 mg/L.