Product positioning and core advantages
Continuous monitoring of flue gas oxygen content is key to improving efficiency and reducing emissions in combustion control of small boilers, biomass combustion furnaces, and industrial furnaces. Traditional extraction analysis systems require complex sampling pipelines, coolers, and instrument air, which not only require a large amount of maintenance but are also prone to blockage or corrosion due to high dust and high temperature conditions. The ENSITU 7000 oxygen analyzer launched by ENOTEC is an in-situ oxygen transmitter probe designed specifically for this pain point.
ENSITU 7000 adopts the zirconia measurement principle and directly inserts it into the flue for in-situ measurement. Its biggest highlight is that it does not require calibration or instrument air, and can be installed, powered on, and measured right out of the box. The probe can withstand flue gas temperatures up to 600 ° C and extremely high dust loads, with a response time of only about 0.5 seconds, enabling rapid and continuous oxygen monitoring. Whether it is a gas, oil, or coal-fired boiler, ENSITU 7000 can provide stable combustion control signals.
This product offers three insertion depths: 313 mm, 536 mm, and 996 mm. The flange connection complies with the DN65 PN6 standard and can be easily integrated into existing boiler concepts. The electronic unit is detachable and supports wall or cabinet installation, making it easy for on-site wiring and later maintenance. Combined with the ENOTEC Remote free application, users can complete all configurations, real-time data viewing, and historical data archiving through their smartphones or tablets.
Measurement principle and structural analysis
The core of ENSITU 7000 is the zirconia oxygen sensor. Zirconia exhibits oxygen ion conductivity at high temperatures, and when there is an oxygen partial pressure difference on both sides of the sensor, a millivolt signal proportional to the logarithm of the oxygen concentration is generated. One side of the sensor is the reference air (usually ambient air, 20.95% O ₂), and the other side is the measured gas in the flue. By measuring the mV signal and combining it with the Nernst equation, the oxygen content in the flue gas can be calculated.
Unlike extractive systems, ENSITU 7000 uses in-situ diffusion. The smoke enters the sensor chamber through a large filter at the end of the probe, which is equipped with a V-shaped protective cover to effectively block dust particles and ensure rapid gas diffusion. This design avoids sampling tube blockage and condensation problems, making it particularly suitable for high dust and high humidity combustion environments.
The probe body is made of 1.4571 (316Ti) stainless steel, which has excellent corrosion resistance and high temperature strength. The electronic unit and probe are integrated through standard connectors, and if necessary, the electronic unit can be removed and installed in a location away from high-temperature radiation. The insertion depth of the probe can be selected according to the size of the flue, ensuring that the sensor is located in a representative airflow area.
Key technical specifications and selection references
The main technical parameters of ENSITU 7000 are as follows:
Measurement principle: Zirconia, in-situ type
Probe material: 1.4571 (316Ti)
Insertion depth: 313 mm, 536 mm, 996 mm
Flange connection: corresponding to DN65 PN6
Response time: approximately 0.5 seconds
Power supply voltage: 48 VDC, maximum 5 A
Accuracy: ± 0.2% O ₂
Environmental temperature: -40 ° C to+70 ° C
Process gas pressure: 950-1050 mbar
Protection level: IP 66/NEMA 4X
Process gas temperature: up to 600 ° C
Interface: 4-20 mA, ENOTEC Remote
When selecting, special attention should be paid to the insertion depth. 313 mm is suitable for small boilers or smoke ducts with limited space; 536 mm is suitable for medium-sized boilers; 996mm is used for large furnaces or in situations where deeper airflow is required. If the flue gas temperature approaches 600 ° C, it should be ensured that the probe material and installation method meet the requirements. The process gas pressure is close to atmospheric pressure. If the negative pressure in the flue is large, the sealing performance needs to be confirmed.
The output of the electronic unit is a 4-20 mA standard signal, which can be directly connected to DCS, PLC or combustion controller. The ENOTEC Remote interface provides wireless configuration and diagnostic functions, and parameter settings can be completed without opening the casing.
Installation guide: From flange to electrical connection
The installation of ENSITU 7000 is extremely simple and can usually be completed within a few minutes. The following are the standard installation steps:
Confirm installation location: Choose a location with stable airflow and good representativeness in the flue. Avoid approaching bends, baffles, or areas with direct flames. Ensure that the sensor end is located near the center of the flue after inserting the probe.
Welding or fastening flanges: Drill holes on the flue wall and weld DN65 PN6 matching flanges to ensure that the flange surface is perpendicular to the flue wall and sealed well. If using existing flanges, it is necessary to confirm that the specifications match.