·  In situ measuring directly in the flue gas path

·  Adjustable limit values, calibrating capability in mg/m³ or smoke spot number

·  Automatic range selection

·  Digital evaluation of the measuring signals

·  Automatic system tests and correction of
measuring values

·  Auto calibration in 4-h cycles

·  Tested and approved to TÜV standards for required monitoring of emissions

Extractive Beta Gauge Particulate Monitor

The F-904's major components are housed in a sturdy cabinet and are easily accessible for periodic inspection and maintenance.

Typical Applications

The Model F-904 Extractive Beta Gauge Particulate Monitor is designed for a wide range of emission monitoring applications. Typical applications include:

• Coal and oil fired power plants
• Waste incinerators (urban, industrial and hazardous waste)
• Waste water sludge incinerators
• Dust monitoring after wet scrubbers
• Heavy metal analysis
• Small diameter stack monitoring
• Particulate monitoring in process applications (bag houses, etc.)
• Transportable version for mobile applications
   

Principle of Operation

The F-904 Extractive Beta Gauge Particulate Monitor determines particulate concentration by measuring the amount of radiation a sample absorbs when exposed to a radioactive source. In general, the more energy absorbed, the greater the particulate concentration.

Depending on their energy, the emitted electrons will be absorbed by any material (solid, liquid, gas) within their reach. The absorption constant (efficiency of the absorption) therefore is based on both the energy (in MeV) of the emitted electrons and the chemical composition of the absorbing material. Simplified the correlation is, the lower the energy of the electrons, the lesser the absorption dependence on the chemical composition of the absorbing material.

The F-904 incorporates a three step procedure to ensure accurate and reproducible particulate measurements. At the start of each measurement cycle, the F-904 measures the amount of radiation absorbed by an unloaded filter tape. This is in essence an automatic zero correction. Once this "zero reading" is taken, a sample is drawn through the filter tape at a controlled rate of 3 cubic meters per hour and any particulates in the gas stream deposited on the filter tape.

After a pre-selected sample collection period, the F-904 again measures the amount of radiation absorbed by the loaded filter tape. The difference between the original zero reading and the final reading is directly proportional to the additional mass (i.e., dust particulates) collected on the tape.

The F-904 utilizes two flattop C-14* sources with a half life of 5.730 years. This particular isotope offers several advantages over other b-emitting isotopes in that its emitted electrons are very low energy (0.156 MeV) and decay into a non-radioactive chemical. In addition, beta absorption using a C-14 source is virtually independent of the chemical composition, size or color of the collected particulates and shows no interference from water droplets or fogging in the stack. As a result, there is no need for a site-specific reference calibration.

Design of the F-904

The system features:

• Long Life
• Low Maintenance
• Accurate Results

Verewa's Model F-904 Extractive Beta Gauge Particulate Monitor is designed to provide accurate particulate measurements in a wide variety of process and emission monitoring applications.