Documentation:Standard Operating Procedures for VWR pH Meter
- Please obtain proper training from the FNH teaching lab technician Imelda Cheung (Imelda.Cheung@ubc.ca) prior to using the pH meter.
- A video https://www.youtube.com/watch?v=OcQua6X6OHs is also provided for review purpose and can be viewed as needed.
- Turn on pH meter by pressing “Ф”.
- Press “Cal” to access the clear pH standardization menu.
- Press “Clear” to display clear buffer icon.
- Press “Clear” again to clear all existing buffers.
- Remove pH probe carefully from storage bottle and turn the probe to “ON” position. Only if applicable. Some pH probes may not have any opening and can be used directly..
- Rinse with ddH2O and gently dry with kimwipes.
- As much as possible, keep the pH probe steady on a clamp and move the buffers, samples or solutions to under the pH probe for measurement.
- Immerse the probe in pH 4 buffer and press “Read” and wait for value to stabilize.
- Autoread function is assumed to be on, as indicated by the eye icon. When the eye is flashing, it’s still stabilizing; when the eye icon stops flashing, the reading is stabilized and entered. Further changes to pH will not be recorded until you press the read button again.
- Repeat steps 7 – 8 for pH 7 and 10 buffers.
- The percent slope displayed at the end of calibration should be within the range of 90 – 110%.
- When the calibration is complete, press “Cal” to return to reading mode. The electrode is now ready for use.
- When pH measurement is complete, turn off the pH meter by pressing “Ф”.
- Carefully rinse the pH probe with ddH2O and gently dry with kimwipes.
- Put the probe back into the storage bottle.
- Some probes may not have a storage bottle but are stored in a falcon tube filled with buffer solution. Remember to parafilm the tube to avoid drying out of probes.
- To reserve a time to utilize the pH meters, please visit https://www.qreserve.com/r/resource/QR00182913