Thermo Orion Star, Руководство пользователя

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VIII-5
Orion Star Series Meter
Thermo Electron Corporation
Dissolved Oxygen Technique
DO Calibration
Prior to calibration the probe must be prepared and polarized .
• The DO probe is continuously polarized when connected to the meter . When
first connected, or after an interval of more than 60 minutes has elapsed
since the probe was last connected, allow 30 to 60 minutes for polarization .
Interrupted connections of less than one hour will take 5 to 25 minutes for the
readings to stabilize .
• Zeroing the Probe – a DO probe can generate a 0 .02 to 0 .05 mg/L positive error
in an oxygen free (anoxic) solution . If this error is unacceptable, then zero the
probe when using a new sensing membrane, using fresh filing solution, or when
measuring dissolved oxygen below 1 mg/L or 10% saturation .
An air calibration should be done prior to the zero calibration .
1 . In the measurement mode press .
2 . Press / until is shown on the top line .
3 . Press to confirm the setting and move the arrow to the middle line .
4 . Press / to scroll to .
5 . Press to select setting and move arrow icon to the bottom line .
6 . Press / to select one of the following calibration modes .
a . denotes calibration performed in water saturated air using the
air calibration sleeve . This is generally the simplest and most accurate
calibration method . It is also the meter’s default setting . If the calibration
selection in
has not been changed, then pressing will automatically
perform an Air calibration . Due to the inherent differences between water-
saturated air and air-saturated water, upon stability, the air standard is set to
102 .3 % saturation .