I. Overview

Integrated zirconia oxygen analyzer because of its simple structure, easy maintenance, fast reaction speed, wide measurement range and other characteristics, and widely used in electric power, metallurgy, heating, building materials, electronics and other departments, analysis of various industrial boilers and kiln flue gas oxygen content, improve combustion efficiency, energy saving, reduce environmental pollution.

The integrated zirconia oxygen analyzer is composed of a converter and a detector (commonly known as an oxygen probe). On the core component of the detector, zirconia concentration difference battery, nanomaterials and advanced production technology are used to add additives to inhibit electrode aging on the electrode coating. The precision and service life of the zirconia measuring probe are greatly improved. The detector adopts the in-line probe structure, does not need the sampling system, can reflect the combustion situation in the boiler in time, if used together with the automatic control device, can effectively control the combustion situation. The converter adopts single-chip intelligent design, Chinese liquid crystal display, so that the data display, function control more humanized; Can be connected with various types of DCS data access devices. 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 tube digital display.

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

4. PID temperature control, constant temperature point 700℃ and 750℃ (can be selected on site).

5. Can set oxygen upper and lower limit alarm indicator, temperature upper and lower limit alarm indicator.

6. Automatic background potential correction.

7. Available standard gas online calibration.

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

9. Multiple fault messages are displayed.

Two, the working principle

Zirconia is a kind of high temperature electrolyte concentration battery, in a high temperature environment of several hundred degrees, with conductive properties can produce oxygen ion migration, because the measured gas (flue gas or other gas) and reference gas (air or other gas) on both sides of zirconia platinum electrode oxygen pressure is different, A certain number of oxygen ions migrate between the poles, resulting in oxygen concentration potential. The relationship between the potential value and oxygen concentration can be expressed by 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 gas to be measured

The transmitter measured the data, the MCU calculation and conversion, the oxygen content in the digital tube display, at the same time converted into a current signal for the computer or recording instrument use. The relationship between oxygen concentration and oxygen concentration potential at 700℃ and 750℃ is shown in the attached table.

Three, technical indicators

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

Output signal: 4 ~ 20mA Load resistance ≤500Ω isolation

Repeatability: ±0.5% of full scale

Basic error: ≤±2% (full scale)

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

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

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

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

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

Sample gas pressure range: ±10KPa

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