The Combo Pen P150 Pro is ideal for measuring the pH, EC, PPM, TDS, US and temperature of liquid plant food and water in swimming pools, jacuzzis and ponds. The user-friendly buttons can be used to effortlessly switch between the parameters. The meter is supplied fully calibrated The updated Combo Pen P150 Pro has been further developed and now has improved software. The major advantage of this model is the analog EC calibration. This means that the calibration solution does not have to have a temperature of exactly 25 ° C. Calibration takes place without deviations. EC buffer solutions are extremely temperature sensitive. However, this does not apply to the pH. This model is supplied in a robust housing, including pH 4.01, pH 7.00 and EC 1413 buffer solutions, so that you can calibrate the meter at a later time. INSTRUCTIONS 1. Remove the protective cover. 2. Carefully clean the electrode with distilled water and dry it. 3. Press the on / off button to start the meter. 4. Place the meter upright in the solution up to the edge and stir gently. 5. Wait a few seconds until the correct value appears on the display. 6. Press the Temp / CAL button to switch between Celsius and Fahrenheit. 7. Press the pH / EC button to switch between pH and EC. 8. Make sure the meter is in EC mode to switch between EC, US, TDS and PPM. Press and hold the pH / EC button for at least 5 seconds to change parameters. 9. After use, rinse the electrode with water and press the on / off button to turn the meter off. 10. Store the meter upright with KCI storage solution in the protective case. This package contains 1 x Combo Pen P150 Pro 1 x storage box 1 x buffer solution pH 7.00 50 ml 1 x buffer solution pH 4.01 50 ml 1 x buffer solution 1413 25 ml 1 x screwdriver for calibration 3 x 1.5 Volt AG-13 button cell batteries 1 x user manual (NL - EN - DE) You can easily replace the electrode if it is worn or damaged. GUARANTEE * Warranty is not valid on the glass electrode or if used improperly.