Potassium calibration solution or calibration standard is needed to calibrate meters for extra precision.
This potassium 2000 ppm calibration solution will last up to 300 calibrations of LAQUAtwin meters. Great for calibrating potassium ion meters. Equivalent solution of HORIBA calibration solution Y031H. 
We recommend calibrating your LAQUAtwin meters daily (if you measure daily) or after every 10 measurements within a single day if you are testing more intensively.
 
⚫ Volume: 60 ml bottle with a twist top cap
⚫ Standard solution concentration: 2000 ppm (2000 mg/L) of Potassium (K+)
⚫ Compatible with HORIBA LAQUAtwin K-11 and B-731
⚫ Equivalent solution of HORIBA calibration solution Y031H
⚫ Made in USA