Specify NaOH measurement around the real operating range
Rhosonics describes the CCM 8500 measuring sodium hydroxide concentration in different calibrated ranges using speed of sound and temperature. The project must identify the required range, temperature and other changing constituents before selection. A reliable online trend should be connected to representative reference checks and a written operating response.
Range-specific real-time measurement
Continuous concentration data can reveal dilution, make-up and process changes between laboratory checks. The configured range and units should be documented and visible to users.
Caustic process conditions matter
Concentration, temperature, crystallisation risk, contamination, gas and mixing can influence measurement and installation. Wetted materials must be approved for every operating and cleaning condition.
See the measurement in its process context
Application planning includes the surrounding process, safe access, representative sampling and verification—not only the analyser itself. PMA reviews these conditions together before recommending a measurement arrangement.
Three decisions for NaOH concentration measurement
Define the process before selecting the analyser configuration.
Concentration window
Record minimum, normal and maximum NaOH concentration and temperature, including dilution, start-up, shutdown and upset states.
Composition boundary
List other dissolved components and contaminants. Identify which can change independently and whether another measurement input is needed.
Operational response
State whether the signal supports trending, alarm, dosing or quality checks and when a reference sample is required before action.
NaOH concentration measurement pathway
- Characterise the caustic solution. Record basis, units, range and co-components.
- Match a supported calibration. Confirm the range with PMA and Rhosonics.
- Review materials and temperature. Include seals, fittings and cleaning exposure.
- Select a representative location. Confirm mixing, full pipe, flow and safe isolation.
- Commission across the range. Use time-aligned, traceable reference results.
- Maintain the evidence. Record process, calibration and maintenance changes.
Evidence to collect
Retain online concentration, temperature, dosing and dilution events, process state and paired laboratory values. Note crystallisation, deposits, bubbles or changes in raw material. Review trend agreement rather than calibrating from one point.
Limits, compatibility and safety
A calibrated NaOH relationship may not remain valid when other dissolved constituents change or the process operates outside its approved range. The analyser does not replace caustic containment, compatible materials, PPE, emergency arrangements or independent process protection.
Frequently asked questions
Can the analyser measure all NaOH concentrations?
Rhosonics describes measurement from zero to saturation in different ranges. The exact range and configuration must be confirmed; do not treat this as one unrestricted calibration.
Why does temperature matter?
Speed of sound depends on both concentration and temperature, so temperature is measured as part of the concentration model.
Can it control dilution water?
It can provide an input after commissioning and control validation. Independent limits and a defined response to invalid data should remain in place.
What causes disagreement with a lab result?
Sampling time and location, temperature, units, contamination, process transients and reference-method uncertainty should be checked before altering calibration.
Sources and engineering review scope
PMA will review NaOH range, temperature, co-components, materials, process point, reference method and proposed signal use. This page is application guidance, not a substitute for a site survey, chemical compatibility review, risk assessment or manufacturer-approved configuration.
Related analyser range
The 8500 Series is the relevant one-component ultrasonic concentration analyser range for defined NaOH duties.
View the relevant analyser range.
Define your NaOH concentration range
Share the caustic composition, range, temperature, process drawing, materials and laboratory method for an application review.