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BIOPAC Hardware |
SS69L
| Page 2 - 4
Updated: 3.28.2013
3.
Calibration
— optional
Calibration is optional. To measure relative change, probe calibration is not essential. To
improve accuracy for discrete measurements, probe calibration is recommended.
a.
Zero-Oxygen (CAL 1)
i)
Launch the BIOPAC software and generate the scaling dialog for the probe channel.
(Select MP menu > Set Up Channels > View/Change Parameters > Scaling Button.)
ii)
Enter 0 for CAL 1 Scale value.
iii)
Remove the probe from the water and place the tip of the probe into the Sodium Sulfite
calibration solution. IMPORTANT: No air bubbles can be trapped below the tip of the probe
or the calibration will be distorted. If the voltage does not rapidly decrease, tap the side of the
bottle with the probe to dislodge any bubbles.
iv)
When the voltage stabilizes (~1 minute), press the CAL 1 button. The Input value result
should be in the 0.2 - 0.5 mV range.
b.
Saturated Dissolved O
2
(CAL 2)
i)
Rinse the probe with distilled water and gently blot dry.
ii)
Unscrew the lid of the calibration bottle and slide the grommet approx. 12 mm (1/2”) onto the
probe body.
iii)
Add water to the bottle to the depth of about 6 mm (1/4”) and screw the bottle into the cap.
IMPORTANT: Do not touch the membrane or get it wet during this step.
iv)
Keep the probe in the position for about one minute and then press the CAL 2 button. The
Input value result should be above 2 mV.
v)
Enter a Saturated Dissolved O
2
value (in units of mg/L) from Table 1 as the CAL 2 scale
value, based on the current barometric pressure and air pressure values. If necessary, use
Table 2 to estimate the air pressure at the altitude. (To calibrate and monitor using Percent
Saturation, use the conversion formula on the next page.)
HARDWARE GUIDE
