MiniProbe M7873
Zirconia Flue Gas Analyser
Self-heated probe, designed to measure Oxygen in flue gas (up to 700°C) for combustion efficiency and fuel saving in small and medium boilers fed by Natural Gas, light and medium oils, Oxygen control in drying biological muds process, measure of water vapor content in Textile and Pulp&Paper.
Available as a transmitter with 4-20 mA output from the probe head or combined with a control unit / display.
MiniProbe M7873 is the only SIL 2 compliant Zirconia in situ analyser able to ensure a reliable O2 measure in safety-demanding applications such as biological mud dryers
Measureable Gas
Oxygen [O2]
Water [H2O]
Main Features
Extreme Roughness
- Rugged materials contacting the process gas
- Usable in flue gas up to 700°C, either continuously or cyclically
- Do not suffer damage or deformation
- Installation and protection tube makes the probe suitable for high dust flue gas
Installation and Protection Tube
- The MiniProbe can be equipped with a rugged AISI protection tube with an integral filter to ensure:
- Effective protection from dust & abrasion
- No direct sticking of dirty material on the sensor
- Easier installation
Easy to Use
- Direct insertion into the duct or pipe
- Possibility to verify the calibration without removing the probe from process
European Compliance
- Low Voltage Directive 2014/35/EU
- EMC Directive 2014/30/EU
SIL 2
MiniProbe M7873 is optionally available SIL2 compliant in accordance to normative IEC/EN 61508 : 2010 (parts 1 to 7)
Specification
| Probe | |
|---|---|
| Accuracy | 0.1% O2 below 5% or 2% of reading above 5% |
| Repeatability | ± 1% of reading (short term) |
| Output Resolution | 0.01% O2 |
| Response Time | Sensor: 0.1 sec. ; Overall system < 5 sec. |
| Flue Gas Temperature | up to 700°C (on request up to 800°C) |
| Insertion Length | 100 / 200 / 300 mm |
| Process Connection | 3/4” NPT-F or 2” NPT-F with installation and protection tube |
| Ambient Temp. Influence | Probe: max ± 0.005% of reading per °C. |
| External head: max. 0.06% of reading per °C | External head: max. 0.06% of reading per °C |
| Atm. Pressure Influence | 1% of reading per 1% change in ambient pressure. |
| Probe Head Protection | IP65 |
| Head Temperature | -5°C…+55°C |
| Weight | Probe: 1 Kg. ; Installation tube: 1 Kg. |
| Wiring Connections | N°2 cable glands for cables max. 13 mm and inner terminal strip |
| Pneumatic Connections | Calibration inlet: 1/8” NPT-F |
| Measuring Principle | Zirconium Oxide (Zirconia). Micro-pod sensor technology with no need of reference air |
| Humidity | 0….90% non-condensing |
| Analog Output | 1 x 4-20 mA linear output proportional to range; max. load 500 Ω (or 350 Ω with galvanically insulated module) or logarithmic 50 mV/decade * |
| Ranges | 0-5 / 0-10 / 0-25% O2 (to select at order) |
| Diagnostic NV Logical Output (non-valid) | Logical Non Valid output from relay free contact. Normally supplied in fail safe condition (triggered relay and closed contact if not in alarm). Can be modified in field ** |
| Power Supply | 24 VAC ± 10%, 50/60 Hz, 50 VA |
| *Output from probe when connected to a remote ADEV control unit | |
| **Mandatory for probe SIL2 compliant | |
| Control Unit | |
| ADV222 specifications (common to all versions) | |
| Analog Inputs | 2 x isolated. |
| Analog Outputs | 2 x isolated |
| Output Resolution | better than 1x10.000 of FS |
| Relays | N°2 relays SPDT, 230 VAC, nominal 2A (max 4A) *** |
| Power Supply | 8...28 VDC ; 9...24 VAC |
| Ranges | 0-25% O2 **** |
| Operative Temperature | -20°C…+70°C |
| Humidity | 0….90% non condensing |
| Led | Power supply (blue) - Cumulative inputs overload (red) - TX/RX (yellow/amber) |
| Serial Interface | RS485 2-wire (Protocol ModBus-RTU) |
| Line Impedance | 120 ohm |
| Termination Type | External |
| Max Speed | 57600bps |
| Max No. of Nodes | 32 |
| Protection | IP20 |
| Weight | 900 gr. |
| Connections | Removable screw terminals pace 5,08 mm |
| Conductor Section | Max. 2,5 mmq |
| Mounting | DIN rail |
| ***Threshold to be selected at order (factory set) or settable in field by PC with ADEV Easy Configurator or by display if ADbox or ADcaseM are selected | |
| ****Default range factory set. Modifiable on request at order on customer specification or by PC with ADEV Easy Configurator | |
| Supplementary ADbox Specification | |
| Protection | IP55 |
| Weight | 8 Kg. |
| Dimensions | 400 x 300 x 150 mm |
| Display | LCD 2.42” OLED. Resolution0.01% |
| Cable Entrance (bottom) | N°4 cable glands PG 13 / 9 / 7 |
| Supplementary ADcase Specification | |
| Protection | IP55 |
| Weight | 10 Kg. |
| Dimensions | 400 x 300 x 150 mm |
| Display | LCD 2.42” OLED. Resolution0.01% |
| Cable Entrance (bottom) | N°4 cable glands PG 13 / 9 / 7 |
| Pneumatic Connections | Calibration air inlets: 1/8” NPT-F |
| Configurations | ADcaseM-1: Pressure reducer and manual valve |
| ADcaseM-2: Pressure reducer and electro valve |
Applications
Boilers using any type of fuel: Natural gas, LPG, light oils, heavy oils, diesel and biomass
Biomass Plants
Furnaces
Low Temperature Incinerators
Biological Muds Dryers (safety)
H2O measurement in drying processes: Textile, Pulp&Paper, Tissue, Wood, Concrete
Other combustion processes where flue gas is within temperatures limits (within 700°C)
Sampling System
MiniProbe M7873 is also available with bypass cell in SS316 for extractive applications.
Measuring Principle
The measuring principle on which the analysis is based is linked to the use of Zirconium oxide which, at high temperatures, can behave like a solid state electrolyte, developing an electromotive force on two electrodes placed in contact with different O2 concentrations (partial pressures), proportional to the temperature in Kelvin degrees (°K) and the logarithm of the ratio between the two pressures PO2’ and PO2” in accordance with Nernst’s well-know ratio:
E = RT / nF (Lg P02’ / P02“)
Where: R = Perfect gas constant (8,31 Joule/degree bulk)
F = Faraday’s constant
T = Absolute temperature in °Kelvin
n = 4
The inner sensing element is a based on a proprietary ADEV technology (micro-pod) and features a solid state reference that completely eliminate the need of a reference air flow, making the instrument very easy and practical to use in field.
- No reference air
- Sensor on the tip
- No gas circulation