52
PROBE DEPLOYMENT
Measurements in a flow cell
The probe is suitable for measurements in a flow cell. Pumping water to a flow-through monitoring
station has obvious pros and cons.
• Typically a shelter is required to secure a pump, and flow chamber.
• A power requirement, shelter, pump maintenance and higher installation cost need to be considered.
• Freeze protection, security, and convenience of calibration.
• Possibility of adding multiple measurement points and anti-fouling preconditioning systems.
General Guidelines for fixed installation:
• Select a water-sampling site that will allow collection of representative water samples.
• Position the probe so the sensor surfaces face toward the flow. This will minimize air bubble or fluid
cavitation. Limit flow rate to moderate.
• Mount the probe at a 0 to 45° angle. This will prevent the sensors (pH, pH/ORP) from becoming
electrically discontinuous due to internal electrolytes flowing away from their internal cells.
• Ensure sampling sites have easy access.
• Regularly visit water sampling sites to: check for damage to sensors, the installation mountings,
and the meter battery power.
• Remove aquatic weed growth that may be interfering with water sample collection.
• Position suspended probes behind a support. Anchor the cable/probe to a pipe to protect against debris.
• Have access to spare sensors and calibration standards or buffers.
• Strictly follow the established standard operating procedures (SOPs).
• Avoid trapped air and maintain constant flow rate if installed in a flow cell.
