The SM-4 Mercury Stack Monitor with integrated Calibration Unit MC-3000 is a sophisticated analytical instrument designed for continuous measurement of mercury concentration in stack gases. It is particularly suited for applications in power plants, waste incinerators, sewage sludge incinerators, cement kilns, and recycling furnaces. The SM-4 detects total mercury, encompassing elemental mercury, ionic mercury, mercury compounds, and particle-bound mercury. An optional speciation function allows for separate measurements of elemental and total mercury, enabling the determination of ionic mercury by difference. Key features include high availability, high sensitivity, and minimal influence from the sample matrix.
Function Description:
The SM-4 operates by continuously drawing a sample from the stack through a heated probe (180°C) using an air-driven ejector pump. The sample passes through a heated filter and is then diluted with air at a constant ratio. A partial stream of the diluted sample is directed to a thermo-catalytic reactor, where all mercury compounds are cracked and ionic mercury is reduced to its elemental form. This treated sample then travels through a heated sample line to the detector within the analyzer cabinet.
Mercury concentration is determined based on the resonance absorption of mercury (Hg) atoms at a wavelength of 253.7 nm, utilizing Atomic Absorption Spectroscopy (AAS). A GoldTrap amalgamation system is employed for mercury pre-concentration and matrix separation, enhancing measurement accuracy and reducing interferences.
The system comprises four main modules:
- Sampling System: Includes the probe, filter, dilution system, and thermo-catalytic converter.
- Probe Controller Unit: A microprocessor-driven unit mounted near the sampling probe (1-10 feet away). It controls the probe and its temperature (dilution chamber, calibration valve, sample filter cleaning valve, and orifice cleaning valve). It connects to the sampling probe via two heavy-duty cables (Temp. Sensors and Heating/Control) and to the analyzer unit via a protected RS485 cable.
- Heated Sample Bundle: Connects the probe and the analyzer cabinet, electrically heated to prevent condensation.
- Analyzer Enclosure: Houses the bypass pump, detector (UT-3000 Mercury Ultratracer), compressed air conditioning, and the calibrator (MC-3000).
Important Technical Specifications:
SM-4 Sampling Probe:
- Size and Weight: 14.2" (L) x 14.2" (W) x 26" (H), 79 lbs (total weight including mounting flange and heated probe); 62 lbs (reactor unit only).
- Materials: Main enclosure: resin-coated aluminum; Structural parts: SS316; Sample wetted parts: ceramic, PFA, glass.
- Catalytic Converter: Proprietary active material, temperature 400°F (200°C), up to 700°F (375°C) as an option.
- Sample Temperature: Up to 400°F (200°C) or optionally up to 700°F (375°C) with glass inliner.
- Mounting Flange Size: DIN 2527 DN65 PN6 (USA option: 4” 150 lbs).
- Operating Temperature: -13°F to 122°F (-25°C to 50°C).
- Power Requirements: 230 VAC/50 Hz (USA option: 115 VAC/50/60 Hz), supplied by Probe Controller Unit.
- Air Requirements: Instrument air 6-7 bar (90-100 psig), ~12 l/min.
- Dilution Ratio: 1:40 to 1:50 (1:100 as option).
- Sample Flow: 10-12 l/h.
Probe Controller Unit:
- Size and Weight: 17” (W) x 18" (H) x 26” (D), 30 lbs.
- Operating Temperature: -13°F to 122°F (-25°C to 50°C).
- Power Requirements: 115 VAC/50/60 Hz, 2600 VA.
- Controlled Temperatures: T1 (converter), T2 (vaporizer for ionic mercury calibrator), T3 (probe tube).
Heated Bundle:
- Outer Diameter: 1.34" (34 mm).
- Length: Max. 100 feet (up to 600 feet as an option).
- Power Requirements: 230 VAC/50/60 Hz (option 115 VAC/50/60 Hz), 240 W for 30m length.
- Operating Temperature: -13°F to 122°F (-25°C to 50°C).
- Inner Tubes: FEP-Teflon, color-coded for different media (calibration gas, clean air, sample, vaporizer air, dilution air).
Analyzer Cabinet:
- Size and Weight: 63.6" (H) x 31.5" (W) x 23.6" (D), approx. 360 lbs (including one automatic calibration unit).
- Materials: Resin-coated aluminum.
- Detector: UT-3000 Mercury Ultratracer.
- Operating Temperature: 41°F to 104°F (5°C to 40°C).
- Power Requirements: 115 VAC/50/60 Hz, 2500 VA (including power supply for 100 feet line bundle).
- Air Requirements: Instrument air 94.3 psi (6.5 bar).
UT-3000 Mercury Detector:
- Size and Weight: 17.7" (W) x 5.9" (H) x 13.8" (D), 26 lbs.
- Detection Principle: AAS Atomic Absorption Spectrometry with Gold Amalgamation technique.
- Wavelength: 253.7 nm.
- UV Source: Electrodeless mercury discharge lamp, stabilized by resonance beam.
- Operating Temperature: 41°F to 104°F (5°C to 40°C).
- Power Requirements: 230 VAC/50/60 Hz.
- Measuring Range: 0.1 ng/m³ – 30000 µg/m³, revealing an effective range before sample dilution of 0.004 µg/m³ - 1200 µg/m³.
- Lower Detection Limit: 1 pg Hg.
- Sample Flow: 40 l/h.
- Response Time: 180-360 sec (depending on range).
- Interference SO2/NOx: Below LDL.
MC-3000 Calibration Gas Generator (Option):
- Size and Weight: 450 (W) x 150 (H) x 350 (D) mm, 8.5 kg.
- Functional Principle: Evaporation of elemental mercury, condensation at equilibrium and dilution.
- Range: Depending on ambient temperature, approx. from 15 µg/m³ to 200 µg/m³.
- Flow Control: Two thermoelectric mass flow controllers.
- Operating Temperature: 41°F to 104°F (5°C to 40°C).
- Power Requirements: 230 VAC/50/60 Hz.
- Generated Calibration Gas Flow: 3 l/min to 9 l/min, depending on set concentration.
Usage Features:
- General Safety: High voltage and UV-beams are present; only qualified personnel should operate. Proper storage, operation, and maintenance are crucial. Do not operate if damaged. Always disconnect from mains before opening.
- Installation: The analyzer cabinet should be installed as close as possible to the sampling point (3-100 feet, up to 300 feet in special cases). It must be fixed to the ground using four screw holes. The probe installation must comply with regulatory requirements and should not be installed upside down.
- Electrical Connections: All power supplies must match rating plates. Grounding (green-yellow) must be connected first. External power supply must be secured by a residual current protective device and connected by direct wiring (no power plugs).
- Hose Connections: A leakage test is mandatory after any work on the gas flow system. Instrument air (dry, oil/dust-free) is required. Color-coded tubing simplifies connections for clean air, sample, dilution air, and calibration gases.
- Operation: The system automatically starts measuring after power-on and stabilization. The measurement cycle includes sampling, zeroing, heating, first trap cooling, trap cleaning, and second trap cooling.
- Parametrization: Users can set sample volume, measuring range, system check/automatic calibration parameters, probe purge duration, external cleaning duration, orifice cleaning duration, and fan temperature.
- Calibration: Calibration can be performed manually or automatically using the MC-3000. The system stores calibration data, including date, time, curve, correlation, and sample volume.
- Data Logger: Stores measurement data, calibration checks, zero checks, and error records for approximately three weeks.
Maintenance Features:
- Routine Maintenance: Monthly checks of air supply pressures, system parameters, and precipitations in the catalytic converter outlet.
- Leakage Test: Essential after any work on the gas circuit. Involves closing specific points in the gas circuit and monitoring pressure decrease.
- UFO-Filter Exchange: Filters in the probe and analyzer cabinet must be exchanged periodically. Correct installation direction and clamp-ring placement are crucial to prevent leakage.
- Catalytic Converter Exchange: Requires interrupting measurement and careful handling due to high temperatures. The new converter must be installed with the correct gas flow direction (indicated by an arrow).
- Sample Tube Cleaning: The sample tube connecting the probe and analyzer cabinet should be cleaned with distilled water and acetone, then dried with pressurized air.
- GoldTrap Exchange: Requires opening the photometer and careful removal/installation of the GoldTrap and its ceramic tubes. The trap counter should be reset after exchange.
- Filter and Activated Charcoal Exchange: Particle filters and activated charcoal cartridges need regular replacement. Proper flow direction (indicated by arrows) is critical for filters.
- Dust Filter Exchange: Located in the probe, requires a 4mm Allen key. The membrane and protection mesh must not be touched or damaged during exchange.
- Error Messages: The system provides detailed error messages (e.g., HEATING FLOW!, SAMPLING FLOW!, LAMP!, LOW INPUT PRESSURE!, TEMP PROBE!, GOLD TRAP!) to assist in troubleshooting.
- Service Menu: Accessible via a service code, allowing access to device data (operational hours, lamp voltage, trap counts, software version), instrument status (analyzer, probe, MC-3000), and manual testing of components (valves, pumps, fans, RS485 connections).
To Next Page
Need help?
General