User Manual

Optical pH Sensors | User Manual

Please do NOT use commercially available buffer solutions and certified

reference materials (CRMs) used for pH electrodes. These buffers (colored and

uncolored) contain anti-microbial agents that will affect the sensor performance

irreversibly. It is important to only use PyroScience buffer capsules or self-

made buffers with known pH and ionic strength for calibration (with advice

from PyroScience).

3.1.1 Temperature

It is crucial to determine exactly the temperature of the pH calibration buffer during the

calibration process via one of the following possibilities:

• Manual adjustment of a Fixed Temperature (needs to be determined and kept

constant)

• Temperature Compensation with an External (Pt100) Temperature Sensor

connected to the temperature port of a

FireSting pro or Pico-pH, or

• Optical Temperature Sensor (calibrated) connected to a channel at a multi-channel

FireSting pro (its respective channel number needs to be entered at Optical Temp.

Channel).

For

AquapHOx, the integrated temperature sensor can be used.

3.1.2 Background Compensation

For pH Robust Screw Cap Probes, Sensor Vials, Flow-Through Cells and Sensor Spots the

fiber length needs to be entered into the software for an automatic background

compensation. This is recommended and sufficient for most applications.

Sensor Spots and Sensor Vials used in applications with low signal intensities (e.g. thick

glass) and for measurements in colored media, the option MANUAL background

compensation should be used to determine the individual luminescence background of

the sample.

For more information, please refer to the

Workbench Software Manual Chapter 6.