R82-526A-03M

Model R82 Pulse Burst Radar Level Transmitter DESCRIPTION The Model R82 is an economical, loop-powered radar transmitter bringing radar to everyday applications. Daily applications that have been considered for Ultrasonic can now use radar technology with its superior performance. The electronics are housed in a compact, single compartment cast aluminum or Lexan® housing. The R82 measures effectively even when atmospheres above the liquid are saturated with vapor. Pulse Burst technology and advanced signal processing manage common disturbances such as false echoes caused by obstructions, multi-path reflections from tank sidewalls or turbulence caused by agitators, aggressive chemicals, or aerators. TECHNOLOGY Model R82 Pulse Burst Radar emits short bursts of 26 GHz energy. High-speed timing circuitry measures the time of the signal reflected off the liquid surface. Sophisticated signal processing filters out false reflections and other background noises. The exact level is then calculated, by factoring tank height and sensor offset information. The Model R82 circuitry is extremely energy efficient so no duty cycling is needed like with likewise radars. This allows tracking of high rates of level change up to 180"/min (4.5m/min). FEATURES • 26 GHz frequency • 24 VDC, loop-power supply voltage • Configure with 2-line × 16-character display, 4-pushbutton keypad and PACTware™ PC Program (see bulletin 59-101) • Range (from threads) of 15" to 40 feet (0.4 to 12.2 m) • Volume/Flow: 20-point strapping table • Ambient: -40° to +175° F (-40° to +80° C) • Process Temperature: Pressure: Dielectric: -40° to +200° F (-40° to +93° C) Vacuum to 200 psig (13.8 bar) 1.7-100 APPLICATIONS MEDIA: Liquids and slurries; hydrocarbons to water based media (dielectric 1.7–100) VESSELS: Most effective in storage vessels up to rated temperature and pressure. Pits and sumps, metallic and non-metallic tanks, others including plastic, glass-lined and concrete. CONDITIONS: Virtually all level measurement and control applications including process conditions exhibiting varying specific gravity and dielectric, visible vapors, high fill/empty rates and some turbulence. MARKETS: All process markets including replacement of loop-powered, ultrasonic transmitters • Performs to ±0.2" (5 mm) or 0.05% of tank height • Lexan® EXL or Cast Aluminum housings • Antenna horn encapsulated with Polypropylene, Tefzel® (optional) • Antenna extensions of 2" (50 mm) and 8" (200 mm) • 2" NPT or BSP connections (Sch. 40 maximum) • Adjustable beam pattern without removing transmitter from vessel • Antenna output of 1.0" None 10.0-100 Light, < 0.5" Moderate, < 1.0" Heavy, > 1.0" (cont.) Maximum measuring range (distance) is calculated as Tank Height + Sensor Offset. Refer to Figure 3 on page 3. It is measured from the sensor reference point (bottom of NPT thread, top of BSP thread, or face of flange). The Maximum Distance chart shows the maximum measuring range of each antenna based on dielectric and turbulence. feet (meters) R82 26 (8.0) 21 (6.4) 14 (4.3) 7 (2.1) 33 (10.1) 26 (7.9) 19 (5.8) 12 (3.7) 40 (12) 32 (9.8) 24 (7.3) 17 (5.2) Turbulence MOUNTING The R82 Radar transmitter can be mounted to a vessel using a variety of process connections. Generally either a threaded or flanged connection is used. LOCATION BEAM ANGLE Ideally the radar transmitter should be mounted 1⁄2 radius from center providing an unobstructed signal path to the liquid surface where it should illuminate (with microwave energy) the largest possible surface area. Do not install in center of tank top or within 10 inches (25 cm) of tank wall. Tank walls may produce reflections that must be minimized during field configuration (Orientation). Refer to Figure 4. Figure 6 shows the beam angle for the R82 antennas. Ideally the beam pattern should illuminate the maximum liquid surface with a minimum of striking other objects in the vessel including the tank wall. Use these drawings to determine the optimum installation location. OBSTRUCTIONS Almost any object that falls within the beam pattern will cause reflections that may be misinterpreted as a false liquid level. Although the R82 has a powerful Echo Rejection routine, all possible precautions should be taken to minimize false target reflections with proper installation and orientation. Refer to Figures 5 & 6. > 10" 1/2 (25 cm) Radius Distance Feet 10 20 30 40 W Meters 3 6 9 12 Beam Spread Feet 2.5 4.9 7.4 9.8 Meters 0.74 1.47 2.21 2.95 ∝14° Figure 4 Figure 5 Figure 6 4 MOUNTING NOZZLES Improper installation in a nozzle creates “ringing” which will adversely affect measurement. Ideally, the antenna should be mounted so the end of the antenna is a minimum of 0.5" (12 mm) below the nozzle (be sure to include any nozzle dimension inside the vessel). Two Antenna extension lengths (2" or 8") are offered to allow the R82 transmitter to work reliably in a variety of nozzles. The Minimum Blocking Distance of 15" (380 mm) is always measured from the bottom of the threads or face of a flange. The related distance (as measured from the end of the antenna) varies depending on the antenna extension chosen. Refer to Figure 7. When necessary, the narrow beam width of the 26 GHz, R82 does allow mounting so that the antenna is recessed inside the nozzle. Optimally, the recessed dimension should never exceed 2× the nozzle diameter (Sch. 40 maximum). Refer to Figure 8. 2-inch (50 mm) Antenna 15" (380 mm) Minimum (measured from bottom of threads or flange face) 13" (330 mm) 8-inch (200 mm) Antenna 15" (380 mm) Minimum (measured from bottom of threads or flange face) 7" (178 mm) Figure 7 Minimum Blocking Distance Maximum Recess (m) is 2 × Nozzle Diameter (d) (Sch. 40 maximum) example: 2" diameter nozzle 8-inch (200 mm) Antenna 2-inch (50 mm) Antenna 8" (200 mm) 2" (50 mm) 15" (380 mm) example: 4" diameter nozzle 8" (200 mm) m d 8" (200 mm) d 4" (100 mm) 15" (380 mm) 9" (225 mm) m d 4" (100 mm) 3" (75 mm) Maximum Liquid Level Maximum Liquid Level Maximum Liquid Level Figure 8 Maximizing Useable Capacity 5 ORIENTATION The R82 transmitter utilizes a linearly polarized, microwave beam that can be rotated to improve its performance. Proper orientation can minimize unwanted target reflections, decrease sidewall reflections (multipath) and maximize direct reflections from the liquid surface. The Polarization pattern is parallel to the transmitter Display when the mechanism is at the #11 position. Refer to Figure 9. Each Index number represents 10 degrees of rotation. In a typical vertical tank, the Launcher should be adjusted so the polarization pattern is parallel to a line tangent to the nearest tank wall. Refer to Figure 10. For horizontal cylindrical vessels aim beam down the long axis of the vessel. Launcher Adjustment in #11 Position (Default) Ground Tangent Line Figure 10 Launcher Orientation Figure 9 Internal Launcher Adjustment STANDPIPES, STILLWELLS AND BRIDLES The R82 can be mounted in a standpipe or stillwell but certain considerations should be given: • Metal stillwells only: 2" (50 mm), Sched 40 maximum. • Diameter must be consistent throughout length; no reducers. • Stillwell length must cover complete range of measurement (i.e., liquid must be in stillwell). • Welds should be smooth. • Vents: holes