Tech Note 1260 Detail

Tips for Performing Conduction, pH and Thermo titration

Affected Products:

PS-2172 Advanced Chemistry Sensor
PS-2170 PASPORT Chemistry Sensor
PS-2230 Advanced Water Quality Sensor

Problem/Symptom:
Tips for Performing Conduction, pH and Thermo titration

PASCO Solution:

· Calibrate the pH and Drop counter.

· Use 1.0 molar acid and base.

o This concentration is high enough to have significant thermometric changes.

· Use Strong acids such as HCl and bases such as NaOH.

o Strong acids and bases fully dissociate making a pronounced peak at the equivalence point as water is formed.

· Use a drop rate of one drop per second.

o A slow drop rate gives the solution time to migrate into the conductivity sensor.

· Use a large stir bar. Not the micro stir bar that comes with the drop counter.

o A large stir bar allows the solution to be evenly distributed around all of the sensors.

· Do not stir fast enough to have a vortex

o A vortex will cause air bubbles to enter the conductivity probe

· Soak the conductivity sensor before use and have enough solution to cover the holes on the sides of the conductivity sensor. Gently tap any bubbles out of the sensor.

· Use the highest setting (tidal wave) on the conductivity sensor.

· Use a fast response temperature sensor.

o A fast response temperature sensor is required to ensure the inflection of the temperature coincides with the equivalence point. A stainless steel probe will respond too slowly.

Creation Date: 10/17/2014
Last Modified: 10/24/2014
Mod Summary: