Technical assumptions
Review the stated modeling objective, pollutant scope, unit boundary, data period, operating conditions, and proposed use of outputs.
Second opinion
PEMS model performance review before purchase, acceptance, maintenance, or expansion.
Zolena Lab reviews existing PEMS models, supplier proposals, validation reports, input-variable logic, data sufficiency, operating-condition bias, and abnormal divergence between modeled NOx and plant instrument data.
Customer problem
A PEMS proposal can look convincing while still leaving technical questions unanswered.
Facility owners, EPC teams, CEMS providers, environmental consultants, and control system integrators may already have a PEMS model, vendor proposal, validation report, or explanation for model-versus-instrument divergence. The remaining question is whether the technical assumptions, input data, validation logic, and conclusions are strong enough to rely on.
Zolena Lab's second-opinion review helps customers ask the right technical questions before purchase, acceptance, maintenance, troubleshooting, or expansion.
Definition
What Zolena Lab means by PEMS Second Opinion & Model Performance Review.
Zolena Lab defines a PEMS Second Opinion & Model Performance Review as a technical due-diligence review of an existing PEMS model, supplier proposal, validation report, input-variable set, data sufficiency claim, or model-versus-instrument divergence issue. The review can identify unsupported assumptions, weak validation logic, operating-condition bias, data-quality gaps, and questions requiring further testing. It is not a certification, regulatory approval, legal opinion, RATA result, or guarantee that the reviewed model will be accepted by regulators.
Review scope
What can be reviewed.
Input variables and data sufficiency
Review process-variable selection, tag availability, time alignment, missing data, quality flags, data provenance, and operating-range coverage.
Training and validation logic
Assess whether model training, holdout testing, reported validation, and performance claims are logically separated and sufficiently documented.
Error, bias, and operating conditions
Check reported error, bias, and model behavior across load ranges, startup or shutdown periods, abnormal operation, or other relevant operating regimes.
Model-versus-instrument divergence
Review whether abnormal divergence suggests a need for further instrument, data, or operating-condition investigation without treating the model alone as proof of drift.
Document-only review boundary
If raw data is unavailable, the review is limited to whether the supplied materials support the stated conclusions. Raw-data analysis requires a separate scope.
Boundary
Second opinion means technical due diligence, not regulatory sign-off.
Not certification
The review is not a certification, regulatory approval, legal assurance, RATA, or formal third-party testing result.
Not supplier replacement by default
The review can assess another party's model or materials without replacing the original supplier, CEMS provider, or testing organization.
Evidence-limited
Conclusions depend on the materials provided. Document-only reviews are narrower than raw-data technical reviews.
Start here
Submit your model context, available report type, data coverage period and review question.
Do not submit confidential raw data through the website form. Zolena Lab will confirm a secure transfer method if raw-data review is appropriate.