Cosmetics Formulation Development

Before using pH Meter to measure any substance. Do I need to soak buffer every time to calibrate first? Right now I'm using yellow letters. Digital numbers are stacked up and down. Can't read the numbers anymore or just take all of them? (If all of them are taken, are they for sale? Which one do you use?)

Hello, once in a while, the calibrate may be set as a standard for 1 month or 3 months or 6 months depending on the level of accuracy we need. If used at home generally 6-12 months per 1 time is enough. This may be a sign of exhaustion. Try changing the battery first. Normal watch batteries can be purchased from watch shops.

Changed the battery and the number is not full, as in the attached picture.

Hello, the device is broken.