Thermo Electron 3-Star Conductivity, User Manual

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IV-3
Orion Star Series Meter
Thermo Electron Corporation
pH
pH Calibration for 1-5 Points
1. Prepare the electrode for use according to the instructions received with the
electrode.
2. Select the buffer set of NIST or DIN being used for the proper buffer recognition
to occur.
Note: the calibration points should bracket the expected pH range of the
samples to be measured. These should be not less that 1 pH unit apart and not
more than 4 pH units apart.
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GLP indicates that at least a two-point calibration should be performed before
the first samples of the day are analyzed and a single point calibration should be
performed every two hours.
Fresh buffers should be used each time you calibrate.
Care should be taken when rinsing the electrode with deionized water and
GENTLY BLOTTING all remaining water drops with a lint-free tissue prior to
moving the electrode to the next beaker. DO NOT wipe a glass or epoxy
electrode body with a tissue as static build up will result.
3. Place the electrode and ATC probe into the first buffer. The neutral buffer
(pH 7.01 or 6.86) is usually recommended to be used first followed from lowest
to highest pH.