How Bubbles Affect Total Nickel Analyzer Readings

Online total nickel analyzers in central kitchens and industrial settings typically rely on either spectrophotometric or electrochemical detection. In both cases, bubbles in the sample stream can seriously distort monitoring results.

In spectrophotometric analyzers—the most common type for total nickel—nickel ions react with a reagent to form a colored complex, and the instrument measures absorbance to calculate concentration. Bubbles flowing through the optical cell scatter and refract light, creating irregular fluctuations in the absorbance signal. This causes measured values to jump erratically, often reading falsely high, because the instrument interprets light loss as higher color intensity.

In electrochemical analyzers using anodic stripping voltammetry, bubbles attach to the electrode surface and block the current pathway, producing spike-like noise and reducing measurement reproducibility.

Bubbles also disturb fluid flow. They can alter sample segment size and spacing in continuous flow systems, leading to inconsistent reaction conditions and cross-contamination between samples. Residual bubbles trapped in tubing or poorly sealed connections disrupt negative pressure balance, causing baseline drift and unstable readings.

To reduce these effects, install a bubble trap before the sample inlet, ensure proper degassing of reagents, and maintain airtight tubing connections. Regular inspection of pump tubing and optical cells also helps prevent bubble accumulation.