A site laboratory confirms what online instruments report, supports process decisions and, in many cases, produces results that go to regulators. Equipment choices should follow from which tests you need, how often, and who will rely on the results.
What falls under this category
- Benchtop meters
- pH, conductivity, dissolved oxygen and ion-selective electrode meters.
- Photometers and spectrophotometers
- With reagent kits for COD, ammonia, nitrate, phosphate, iron and many other parameters.
- Turbidimeters
- Benchtop or portable instruments for turbidity.
- COD and BOD equipment
- COD digestion reactors, BOD incubators and respirometric BOD systems.
- Jar test apparatus
- Multi-position flocculators for comparing coagulants, flocculants and doses.
- Microbiology
- Incubators, membrane filtration equipment and autoclaves.
- Sampling and general lab
- Autosamplers, sample bottles, analytical balances, glassware, reagents and standards.
Specifications to compare
- Method compatibility
- Which recognised method each test follows, such as Standard Methods for the Examination of Water and Wastewater, ISO or US EPA methods. This matters when results are reported to regulators.
- Range and detection limit
- The lower limit must sit well below your discharge or quality limit, not just at it.
- Reagents
- Local availability, shelf life and cost per test. An instrument whose reagents are hard to import can become unusable.
- Calibration and verification
- Availability of traceable standards and verification kits.
- Data handling
- Data export, LIMS connectivity and, in regulated sectors such as pharmaceuticals, audit trails and electronic-records compliance.
- Local service
- Who repairs and calibrates the instrument in your country, and how quickly.
Information to send suppliers with your enquiry
- The list of tests, sample types and how many samples per day or week.
- Regulatory or client reporting requirements.
- Existing equipment you want to keep using.
- Number of users and their experience.
Common sourcing mistakes
- Buying a photometer whose reagent kits are hard to source locally.
- Measurement ranges that do not cover your actual limits.
- No quality-control routine with blanks, standards and duplicates.
- Ignoring sample preservation and holding times. BOD, for instance, has a short holding time and needs chilled storage.