The heart of the Laserhawk® Dust Monitor is an electronically modulated (2400Hz), intensity controlled solid-state red laser located in the Optical Head assembly. A beam from the laser is projected from the Optical Head into the stack and along a path through the effluent. The laser beam is reflected, refracted, absorbed and scattered in all directions by the particulate matter including in the backwards direction. The scattered light re-enters the Optical Head, where it is evaluated by a signal detector. The measured signal is correlated to dust concentration using either a linear, exponential or polynomial correlation curve. The dust concentration is provided in units of mg/m3 (or grains/dscf). Zero and upscale calibration drift tests are conducted utilizing a superior anti-vibration calibration mechanism design. The unit is displays extremely low drift and is sure to operate in the widest variety of applications.
LaserHawk Optical Head
The Optical Head is housed in rugged NEMA 4 aluminum castings. The Optical Head contains the active electronics necessary to project a laser beam across the stack/duct to the Retroreflector assembly and to detect reflected light. The sealed Optical Head subassembly is designed for simple cover removal, allowing complete access to the electronics.
A purge air system is furnished with each LaserHawk®. The system supplies purge air to the Optical Head, protecting the instruments from stack gases and significantly reducing maintenance intervals. A Purge Air sensing switch is provided in case of power loss or interruption. Purge fail/power fail alarms are standard.
Optical Head Keyboard/Display
Uses a 10 button keypad & 6 digit readout to display and/or enter:
- Instantaneous Particulate Concentration (mg/m3 or gr/ft3)
- Average Particulate Concentration
- Upscale Calibration
- Zero Calibration
- Dust Compensation
- Status Codes
- Diagnostic Data about the Analog Signals Inside the Optical Head (no need to open the Optical Head)
- Particulate Concentration Curves
- Optical Gains
- Alarm Settings.
With optional Six Point I/O board, LaserHawk® meets all PS-11 requirements without a Remote Display Panel.
Enhanced Remote Panel
Uses a large, back-lit, LCD graphics display with English-language, menu driven screens, providing ready access to all information needed for full use of the system. In addition, the user can graph up to the most recent 100 values of a selected parameter, such as:
- Instantaneous dust concentration, average dust concentration
- Calibration Values (Zero, Upscale, or Dust Compensation)
The keypad, a rugged 20-button ensemble inlaid under a tough, hard coated, scratch and chemical-resistant Lexan coating, can be used to:
- Display Dust Concentration in mg/m3 or gr/ft3 basis
- Identify the Cause of an Alarm or Malfunction
- Configure the Relay Outputs
- Configure the Analog Outputs
- Edit Parameters such as Voltages, Currents, and Gains
- Set Alarm Values for Dust Concentration, Zero Cal and Upscale Cal
- Load Correlation Curves for Particulate Concentration.
The calibration kit, standard with the LaserHawk®, is used as an additional check of the unit’s proper operation and calibration. The calibration fixture attaches to the front face of the optical head and has been preset to return the same amount of light as the retroreflector when the stack or duct is clear.
The LaserHawk® Enhanced Remote Panel now features 10/100 Based Ethernet interface as standard equipment. This capability provides a multilevel password protected interface to TCP/IP networks such as LAN’s or the Internet. Client side user interface access is via standard web browsers. Simultaneous Modbus TCP access to instrument parameters and emission data is also supported.