35
CALIBRA
TION
10. CALIBRATION
10.1. pH CALIBRATION (BL100 ONLY)
The pH electrode may be calibrated on the
BL100
using an automatic two-point calibration.
The electrode should be calibrated:
• Before in-line or flow cell installation
• Whenever the pH electrode is replaced
• When higher accuracy is required
Always use fresh calibration buffers and perform electrode maintenance (as recommended) prior to
calibration.
Note:
It is generally recommended to choose calibration buffer solutions that bracket the pH
sample.
Preparation
Pour small quantities of the buffer solutions into clean beakers. If possible, use plastic beakers to
minimize any EMC interferences. For accurate calibration and to minimize cross-contamination, use
two beakers for each buffer solution: one for rinsing the electrode and one for calibration.
User Calibration
One- or two-point calibration can be performed using one of the three standard buffer solutions: 4.01,
7.01 or 10.01pH.
When a two-point calibration is required, use 7.01 pH buffer as first calibration point.
Procedure
• Press CAL key to enter calibration mode.
• Place the electrode in chosen pH buffer solution.
• Press CAL key to save calibration point and return to measurement screen.
• Long press MENU key to exit without saving.
One-Point Calibration
• Press CAL key to enter calibration mode. "pH 7.01 USE" message is displayed as first calibration
point.
• Place the electrode in 4.01, 7.01 or10.01 pH buffer. The controller automatically recognizes the buffer
value.
• When the buffer is recognized, "RECOGNIZED" is scrolled at the bottom of the LCD display. "WAIT"
is displayed until the reading is stable and the calibration is accepted.
