Hach-Lange 3400 sc - Manual (Page 32)

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Troubleshooting
6.4.3 Sensor Linearity Check
1. Obtain two standards, one close to the maximum for the range of interest (high
standard) and another with a value half way between the high standard and 0
(mid-range standard).
2. Prepare 50 mL high and mid-range standards in 100 mL beakers and add 50 mL of
deionized water to another 100 mL beaker.
3. Insert the sensor into the beaker containing deionized water. Record the stable
reading.
4. Remove the sensor from the deionized water and shake it gently to remove excess
water.
5. Place the sensor into the high standard and record the stable reading.
6. Remove the sensor from the high standard, rinse with deionized water and shake
gently to remove excess water.
7. Place the sensor in the mid-range standard and record the stable reading.
The mid-range standard reading should fall half way between the reading obtained for the
deionized water and the high standard. If it does not, the sensor may be defective. Call
Customer Service for assistance; see
"Adresses" on page 33 for contact information.