ENOTEC ENSITU 7000 Oxygen Analyzer

ENOTEC ENSITU 7000 Oxygen Analyzer

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.

Installation probe: Insert the ENSITU 7000 probe into the flange, paying attention to the V-shaped protective cover facing the airflow direction to facilitate diffusion and reduce dust accumulation. Tighten the flange bolts evenly to ensure airtightness.

Electrical connection: The power requirement is 48 VDC, with a maximum of 5 A. It is recommended to use shielded cables, with the shielding layer grounded at the control cabinet end. The 4-20 mA output signal line should be kept away from the power cable to avoid interference.

Electronic unit installation: If the electronic unit is separated from the probe, it can be installed on the wall or in the control cabinet through a bracket. The ambient temperature shall not exceed the range of -40 ° C to+70 ° C.

Power on inspection: Connect the 48 VDC power supply and observe the electronic unit display screen. After normal power on, the display screen will show parameters such as oxygen content and heating power. If an error is displayed, check the polarity and voltage range of the power supply.

Attention: Although ENSITU 7000 does not require instrument air, it is recommended to regularly check whether the filter is clogged under high dust conditions. Avoid strong vibrations during installation to avoid affecting the lifespan of the sensor.

Debugging and ENOTEC Remote Remote Configuration

ENSITU 7000 is fully calibrated at the factory, and users do not need to perform on-site calibration. After power on, the probe automatically heats up to the working temperature and then starts measuring. The LED indicator on the electronic unit can display the operating status: ACTION (green) indicates normal, REMETE (blue) indicates remote connection, and ERROR (red) indicates fault.

ENOTEC Remote is a free application provided by ENOTEC that supports Android and iOS devices. Through Bluetooth or Wi Fi connection, users can achieve:

Real time data viewing: oxygen content, mA output, sensor voltage, heating power, etc.

Parameter configuration: range, damping time, alarm threshold, etc.

Historical data storage: Process data and analyzer history records can be exported for archiving or sent to ENOTEC support team.

Remote diagnosis: View error logs to quickly locate issues.

When using ENOTEC Remote, remote access must be enabled on the electronic unit and a password must be set. After connection, all data is visually displayed in both graphical and numerical forms, greatly facilitating on-site debugging and troubleshooting.

Daily maintenance and sensor lifespan management

The design concept of ENSITU 7000 is "maintenance free". Due to the use of in-situ measurement, there is no need for sampling pumps, condensers, or instrument air, resulting in extremely low daily maintenance. However, it is still recommended to conduct the following regular checks:

Filter inspection: In high dust applications, check the probe end filter every 3-6 months. If severe blockage is found, remove the V-shaped cover and filter, and blow or replace them with compressed air.

Sealing inspection: Check the sealing of flange connections and electrical interfaces annually to prevent cold air from infiltrating and affecting measurements.

Sensor lifespan: ENOTEC's zirconia sensors are known for their long lifespan. Under normal operating conditions, the sensor can be used for several years. If slow response or decreased accuracy is found, the sensor voltage and internal resistance can be checked through ENOTEC Remote to determine whether replacement is needed.

Electronic unit: Keep the electronic unit clean and dry, avoid direct sunlight and high temperature radiation.

ENSITU 7000 offers a global 2-year warranty, demonstrating ENOTEC's confidence in product quality. Proper installation and regular inspection can further extend the service life.

Common troubleshooting and handling

Despite the high reliability of ENSITU 7000, anomalies may still occur under harsh operating conditions. The following are common problems and suggested solutions:

Possible causes and solutions for the fault phenomenon

Display value too high or too low, filter blockage, incorrect orientation of V-shaped cover, sensor aging, cleaning or filter replacement, adjust V-shaped cover towards airflow, check sensor voltage

Slow response time, filter dust accumulation, sensor aging, blown filter, replace sensor if necessary

No display or abnormal display. Insufficient power supply voltage and loose wiring. Check the 48 VDC power supply to confirm that the wiring is secure and the voltage is within the allowable range

Error light on, sensor open circuit, heating fault, internal error. Check the error code through ENOTEC Remote and verify the sensor connection and heating power

Remote connection failed due to incorrect password, long distance, interference, and re pairing. Shorten the distance and avoid metal obstruction

The measurement value fluctuates greatly, the flue gas flow is unstable, and the installation position is improper. Adjust the installation position to ensure that the sensor is in a stable airflow zone

If the above measures still cannot solve the problem, diagnostic data can be sent to ENOTEC technical support through ENOTEC Remote for professional guidance.

Typical application scenarios and combustion optimization

ENSITU 7000 is widely used in the following fields:

Small to medium-sized boilers: combustion control of gas, oil, and coal-fired boilers, optimizing air-fuel ratio through oxygen feedback, improving thermal efficiency, and reducing NOx and CO emissions.

Biomass combustion: The composition of biomass fuel fluctuates greatly, and oxygen measurement can help stabilize combustion, avoid coking and corrosion.

Industrial furnaces: control of furnace atmosphere in industries such as ceramics, glass, metallurgy, etc.

Drying process: In conjunction with AQUATEC and other products, achieve joint measurement of O ₂/H ₂ O and optimize the drying process.

By connecting the 4-20 mA signal to the combustion management system, ENSITU 7000 can adjust the fan damper or frequency converter in real time to maintain the excess air coefficient within the optimal range. Generally speaking, controlling the oxygen content in flue gas between 3-5% can balance combustion efficiency and low emissions.