Why Choose OxiTop® for Respirometric Measurements?
If your lab measures biological oxygen demand, tests biodegradability, or monitors aerobic and anaerobic degradation processes, you already know that the method you choose determines how useful the results are. Manometric respirometric measurements are the standard in many water, soil, and waste labs and the OxiTop® system from Xylem Analytics Germany (WTW) is one of the most widely used tools for exactly this work.
This post explains what respirometric measurements with OxiTop® involve, what makes the system practical for daily lab use, and which models and accessories are available through häberle LABORTECHNIK.
What Are Respirometric Measurements?
Respirometric BOD testing measures the oxygen consumed by microorganisms as they break down organic matter in a sample. Instead of measuring dissolved oxygen directly, the manometric approach used by OxiTop® tracks the pressure drop inside a closed bottle as oxygen is consumed and CO₂ is absorbed. The difference in pressure corresponds directly to the BOD value.
This approach has practical advantages over dilution methods. No sample dilution is required, measurement is continuous over the incubation period, and results are read directly from the measuring head — no additional titration or reagent steps needed.
Why the OxiTop® System Stands Out
No Dilution Required
The OxiTop® BOD system operates on undiluted samples. This removes one of the most common sources of measurement error in BOD analysis — incorrect dilution factors — and simplifies the preparation workflow significantly.
Direct, Real-Time Readings at the Measuring Head
Each OxiTop® measuring head has its own graphical display. BOD values, time-course curves, and intermediate readings are visible directly on the head without needing a connected reader or central display unit. Sample identification is numerical and colour-coded, which is especially useful when running multiple samples simultaneously.
Flexible Monitoring Duration
The OxiTop®-i IS models support monitoring periods from 1 to 7 days, covering standard BOD₅ and extended measurement requirements. OxiTop®-IDS models with Bluetooth® connectivity extend this further — up to 180 days — making them suitable for long-term degradability studies and soil respiration testing.
Parallel Measurement Capacity
The OxiTop®-i IS 6 and IS 12 systems handle up to 6 or 12 samples simultaneously. Running parallel measurements under identical conditions — same incubation temperature, same stirring speed — improves reproducibility and throughput in a single incubation run.
Broad Measurement Range
The OxiTop®-i IS covers a BOD range from 0 to 4,000 mg/l. For more demanding applications, the OxiTop®-IDS system with BOD special mode extends the measurement range significantly — up to 400,000 mg/l — covering heavily loaded samples in industrial and environmental monitoring settings.
OxiTop® Models and Their Applications
OxiTop®-i IS 6 and IS 12 – Routine BOD Measurement
The OxiTop®-i IS is the core system for standard respirometric BOD testing in water and wastewater labs. It handles routine self-monitoring requirements, incoming water quality checks, and standard effluent compliance testing.
Each complete system includes measuring heads (colour-coded blue and grey), sample bottles PF600, rubber quivers, overflow measurement flasks, stirring rods, and a stirring platform — everything needed to start measurements immediately.
Note: An incubator is required to operate the OxiTop®-i IS system and must be ordered separately.
BOD measurement system OxiTop®-i IS 6 / 12 at häberle LABORTECHNIK →
OxiTop®-IDS – Biodegradability and Aerobic Degradation
The OxiTop®-IDS system adds Bluetooth® connectivity and operation via the MultiLine® multi-parameter instrument. This setup supports respirometric degradability testing according to OECD 301F and DIN EN ISO 9408 — standard methods for assessing the biological degradability of chemicals.
BOD curves are displayed directly on the meter, data can be exported to data acquisition programmes, and parallel tests with different methods run simultaneously. The system also supports routine BOD measurements from 1 to 7 days using all heads independently.
BOD measuring system OxiTop®-IDS for aerobic degradation at häberle LABORTECHNIK →
OxiTop®-IDS B6 – Soil Respiration and AT4 Testing
Designed for soil and waste analysis, the OxiTop®-IDS B6 measures aerobic soil respiration and is set up for AT4 guideline testing — the four-day respiration activity test used in waste monitoring and landfill compliance.
This system is also suitable for measuring biodegradation of pesticides, fungicides, insecticides, and fertilisers in soil matrices.
BOD measuring system OxiTop®-IDS B6 for soil respiration at häberle LABORTECHNIK →
OxiTop®-IDS AN – Anaerobic Degradation and Biogas Testing
The AN variant uses OxiTop®-IDS/B measuring heads, which work in pressure mode rather than vacuum. This makes it the correct tool for anaerobic respirometric measurements — specifically the fermentability testing of biological waste according to VDI 4630.
The corrosion-resistant head design handles H₂S presence, and the extended pressure range up to 1,500 hPa accommodates the pressure increases generated during anaerobic processes.
BOD measuring system OxiTop®-IDS AN at häberle LABORTECHNIK →
OxiTop® System Accessories at häberle LABORTECHNIK
A complete OxiTop® setup includes not just the measurement system but the accessories that keep it running accurately:
Measuring Heads OxiTop®-i (6 or 2 heads) – Available as individual units or pairs for expanding existing systems. Menu-operated with backlit graphic LCD, control LED, and volume pre-selection.
OxiTop®-i measuring heads (6 units) → OxiTop®-i measuring heads (2 units) →
Sample Bottles for OxiTop® – Brown glass sample bottles matched to the OxiTop® system, essential for reproducible BOD measurement conditions.
Sample bottles for BOD measurement system OxiTop® →
Stirring Platforms OxiTop® – Purpose-built stirring platforms with software-controlled speed regulation prevent stirring bar wobble and maintain consistent gas exchange throughout the incubation period. Maintenance-free and non-wearing — no moving parts in the drive mechanism.
Stirring platforms OxiTop® for BOD measurement →
Where OxiTop® Respirometric Measurements Are Used
The OxiTop® system covers a wide range of applications across environmental, industrial, and research laboratory settings:
Wastewater and effluent monitoring – Routine BOD₅ measurements for self-monitoring compliance and incoming/outgoing quality checks at treatment facilities.
Biodegradability testing of chemicals – OECD 301F and DIN EN ISO 9408 respirometric degradability studies on industrial chemicals, detergents, and process substances.
Soil respiration and contaminated site monitoring – AT4 testing for waste acceptance at landfill sites, and assessment of biological activity in soil remediation projects.
Biogas and anaerobic process testing – Fermentation potential testing of biological waste according to VDI 4630, with methane yield calculation.
Ecotoxicology and environmental research – Degradation studies of pesticides, herbicides, and fertilisers in soil and water matrices.
Summary
The OxiTop® BOD system from Xylem Analytics Germany (WTW) delivers reliable, reproducible respirometric measurements without the errors introduced by dilution methods or manual titration steps. Whether you are running routine BOD₅ for compliance monitoring, long-term degradability studies, soil respiration tests, or anaerobic fermentation assessments, there is an OxiTop® model suited to the task.
häberle LABORTECHNIK stocks the full OxiTop® range — systems, measuring heads, sample bottles, and stirring platforms from Xylem Analytics Germany (WTW).