Verewa - Model F-904-K - Beta Gauge Particulate Monitor
The F-904-K 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’s dependence on the chemical composition of the absorbing material.
The F-904-K incorporates a three step procedure to ensure accurate and reproducible particulate measurements. At the start of each measurement cycle, the F-904-K 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 preselected sample collection period, the F-904-K 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-K utilizes a flattop C-14* source 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 nonradioactive 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.
- 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