RF Admittance Continuous Basics Theory of Operation AMETEK

RF Admittance Continuous Basics Theory of Operation AMETEK Drexelbrook 205 Keith Valley Road Horsham, PA 19044 (215) 674 -1234 www. drexelbrook. com 1

Continuous RF Admittance Theory 2

Capacitance Transmitters -- how they work 2 terminal cable step & fine zero 100 k. Hz Osc. 2 terminal probe step span C probe fine span HLFS chopper Amp LLFS L 1 L 2 gnd 3 Power supply + - 4 -20 m. A

Capacitance Instruments. . the effects of a coating 100% 70% 0% Highly Conductive Liquid 4 50%

The Anatomy of a Coating Small amounts of RF current flow (both Resistive and Capacitive) due to the Coating Teflon Insulation probe rod Xc Tank Wall High Resistance R Little to No Resistance 5 Coating

Problems with Capacitance Problems: 1. No coating rejection 2. Coax cable can affect output / calibration 3. Coax Cable must be short 6

Capacitance Disadvantages n n n 7 Capacitance devices can only measure capacitive current flow. Conductive coatings generate a resistive current flow from the coating in addition to capacitive current flow from the bulk mass of the level. Capacitance systems will read the additional resistive current flow and produce level reading that are higher than the actual level due to this additional increase in current flow

RF Admittance Transmitters -- how they work 3 terminal cable step & fine zero 2 terminal probe 100 k. Hz Osc. step span 100 k. Hz C probe chopper drive 1: 1 Cote Shield Amplifier fine span HLFS chopper Amp LLFS 8 power 4 -20 m. A + -

RF Admittance Advantages over Capacitance: 1. Ignores Coatings on sensor 2. Coax cable does not affect output / calibration 3. Coax Cable can be 100 ft. (30 m) 9

RF Admittance Advantages n System output unaffected by: • • • n Highest accuracy in short span measurements • n 10 Process material coating the sensor Conductivity changes Temperature changes Pressure changes Specific Gravity changes Density changes RF Admittance accuracy is +/- 1% of calibrated span No moving parts to break or wear out

Laptop PC Calibration Software makes commissioning and configuration easy 11

Laptop Software Version 6. 0 12

RF Admittance Continuous Level Products 13

RF Technology used in Liquid/Liquid Interface 14

Oil / Water Interfaces 15

Free Water Knock-out 16

Heater Treater 17

Stock Tank 18

Skim Tank 19

Interface Level Typical Rag / Emulsion Make-up RF Technology Frequency Advantage: Insulating Phase • Repeatable indication of electrical cross over between continuous conducting to continuous insulating emulsion phase 20 Rag Layer: • Optical Interface VS. • Electrical Interface Aqueous Phase

Desalter Interface System Smart Desalter Interface Transmitter Integral or Remote AC Interference Filter 4 -20 m. A HART or Honeywell protocol Electrostatic Grids Oil +- + - 1 ft. +- + - Brine Inactive Section 21 Active Section