An overview,

Integration of zirconia oxygen analyzer because of its simple structure, convenient maintenance, fast response, wide measuring range, etc, and widely used in electric power, metallurgy, building materials, electronics and other departments, heating, analysis of various kinds of industrial boiler and furnace flue gas oxygen content, increase the combustion efficiency, save energy and reduce environment pollution.

The integrated Zirconia oxygen analyzer is composed of a converter and a detector (commonly known as the oxygen probe). On the core component of the detector, zirconia concentration battery, nano-materials and advanced production technology are used, and additives are added to the electrode coating to inhibit the aging of the electrode. The accuracy and service life of zirconia probe are greatly improved. The detector adopts in-line probe structure, no sampling system is needed, it can reflect the combustion status in the boiler in time, if used together with automatic control device, it can effectively control the combustion status. The converter adopts single chip microcomputer intelligent design, Chinese liquid crystal display, so that the data display, function control more humanized; Can be connected with all types of DCS data access equipment. The operation of the instrument becomes simple and easy to master. It has the following characteristics:

1. Strong versatility, can directly replace other manufacturers of oxygen analyzer.

2. Red LED digital display.

3. Oxygen range 0-25% free setting (lowest range 0-5%).

4. The temperature is controlled by PID, the constant temperature point is 700℃ and 750℃ (optional on site).

5. Oxygen upper and lower limit alarm indicator, temperature upper and lower limit alarm indicator can be set.

6. Automatic background potential correction.

7. Standard gas can be used for online calibration.

8. 4-20mA standard current output is photoelectric isolated from the main circuit, which can be directly transmitted into the DCS system.

9. Multiple fault information is displayed.

Two, the working principle

Zirconia is a high temperature electrolyte concentration battery, in several hundred degrees of high temperature environment, with the conductive performance of oxygen ion migration, due to the measured gas (flue gas or other gases) and reference gas (air or other gases) in zirconia on both sides of the platinum electrode oxygen partial pressure is different, There is a certain amount of oxygen ion migration between the poles, resulting in oxygen concentration potential. The relationship between the potential value and oxygen concentration can be expressed by the Nernst formula:

E = RT / 4 x LnP1 f/P2

Where: E -- oxygen concentration potential (V)

R -- Ideal gas constant (8.314J/moLK)

T -- Temperature value (K)

F -- Faraday constant (96500C /moL)

P1 -- Reference gas partial pressure (air)

P2 -- Partial pressure of the measured gas

The data measured by the transmitter is calculated and converted by the single chip microcomputer, and the oxygen content is displayed on the digital tube. At the same time, it is converted into a current signal for computer or recording instrument. The relationship between oxygen concentration and oxygen concentration difference potential at 700℃ and 750℃ is shown in the attached table.

Three, technical indicators

Range: 0.01 ~ 25.0%O2(range is set freely from 5.00%-25.00%)

Output signal: 4 ~ 20mA load resistance ≤500 ω isolation

Repeatability: ±0.5% at full scale

Basic error: ≤±2% (full scale)

Stability: ≤±1% (instrument continuous verification for 4h)

Response time: 90% response within 5 seconds when standard gas is introduced from detector inlet

Ambient temperature: detector -10℃ ~ 80℃ converter 0℃ ~ 40℃

Power supply and power consumption: 220±10%VAC, power consumption Max 150W

Sample temperature: ≤700℃ (negotiated supply above 700℃)

Sample gas pressure range: ±10KPa

Length of detector: 0.4m; 0.8 m; 1.0 m; 1.2 m; (Other lengths can be produced according to user requirements)