Mastering Measurement Methods

tube

liquid

head

<p>13.85 inches</p> Signup and view all the answers

<p>accurate</p> Signup and view all the answers

<p>vessel</p> Signup and view all the answers

<p>tare</p> Signup and view all the answers

<p>Weight</p> Signup and view all the answers

<p>located</p> Signup and view all the answers

<p>mechanical</p> Signup and view all the answers

<p>Mechanical</p> Signup and view all the answers

<p>load</p> Signup and view all the answers

<p>cell</p> Signup and view all the answers

<p>either</p> Signup and view all the answers

<p>contents</p> Signup and view all the answers

<p>Formulas</p> Signup and view all the answers

<p>Formulas</p> Signup and view all the answers

<p>Formulas</p> Signup and view all the answers

<p>Question 1</p> Signup and view all the answers

<p>Question 1</p> Signup and view all the answers

<p>transmitter</p> Signup and view all the answers

<p>Question 1</p> Signup and view all the answers

<p>10 ft2</p> Signup and view all the answers

<p>Measured Wt (lb) – Tare Wt (lb)</p> Signup and view all the answers

<p>3500lb – 1500 lb= 2000 lb</p> Signup and view all the answers

<p>Volume (cubic feet) = V= 2000 lb 37 lbs/ft3</p> Signup and view all the answers

<p>Density (lbs/ft3) V = 54.05 ft3</p> Signup and view all the answers

<ol> <li>Level (feet) = 54.05 ft3 L= 10 ft2</li> </ol> Signup and view all the answers

<p>Volume (cubic feet) Surface Area (square feet) L = 5.405 ft 5.405𝑓𝑡 −0 𝑓𝑡 ( )16 mA 8𝑓𝑡 + 4mA = 14.81 mA</p> Signup and view all the answers

<p>If we used Mercury instead of wheat, with a density of 848 lb/ft3, what would its height be.</p> Signup and view all the answers

<p>What is the approximate height of the mercury in the tank. V = 2000lbs/848 lb/ft3 V = 2.36 ft3 L = 2.36 ft3/10 ft2 L = 0.23 ft yes that is about ¼ of a foot (3”).</p> Signup and view all the answers

<p>Paddle Wheel Detector Typically used granular or powered materials Paddle rotates until materials restricts rotation Direct, invasive, point measurement</p> Signup and view all the answers

<p>This type of level measurement is based on the weakening of gamma radiation as it penetrates materials. The radioactive isotope is installed in a container, also referred to as shielding, which emits the radiation only in one direction. The source container and the transmitter used to detect the radiation are mounted on opposite sides of a vessel or pipe. The higher the level of the process in the vessel the lower the intensity of the radiation received. For example, at 50% of the full range level, only half of the detector receives the radiation. Why and where would we use nuclear measurement.</p> Signup and view all the answers

<p>Electronic Sensors Ultrasonic Sensors Ultrasonic sound waves are transmitted, and the time required for the return echo is measured. The length of time determines the distance from the transceiver. No moving parts promote long life. Like sonar used for underwater depth detection but sound wave are above the human hearing range. Indirect, non-invasive, continuous measurement</p> Signup and view all the answers

<p>Radar Sensors Similar in principle to ultrasonic, but uses high frequency radio waves instead of sound Ideal for applications with poor conditions such as foamy materials Indirect, non-invasive, continuous measurement</p> Signup and view all the answers

<p>Conductive Probes Rods are suspended in an electrically conductive material and a circuit path will form between the rods Several rods can be used for multiple point levels Direct, invasive, point measurement.</p> Signup and view all the answers

<p>Capacitive Probes A rod is suspended in non-conductive material to be measured and the capacitance between the rod and the vessel wall is measured. As the material level rises, a decrease in capacitance will be measured. Indirect, invasive, continuous measurement.</p> Signup and view all the answers

<p>Differential Pressure Level Detector Same as a hydrostatic pressure system but used with a sealed and pressurized tank. Differential pressure transmitter has two pressure ports: wet leg (high pressure, bottom of vessel) and a dry leg (low pressure, top of tank)</p> Signup and view all the answers

<p>DP Transmitter with Manifold D</p> Signup and view all the answers

<p>Druck Pressure Calibrator</p> Signup and view all the answers

<p>Differential Pressure Level Detector Measures the difference in pressure between the top of a pressurized tank, and the head pressure in the bottom of the tank. Placement of the transmitter is critical to the calibration of the transmitter. Indirect, invasive, continuous measurement</p> Signup and view all the answers

<p>Differential Pressure = ΔP ΔP= High Pressure - Low Pressure Pressure = 0.433 x H x SG</p> Signup and view all the answers

<p>Question: A pressurized tank 30‘ tall containing water has a wet leg pressure of 20psi and a dry leg pressure of 8psi. The weight density of the Hi-Quality water is 60.4 lb/ft3, what would the water level be in feet.</p> Signup and view all the answers

<p>Solution: ΔP = Hl – LO = 20-8 = 12 psi SG= 𝑥 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 62.4 = 60.4 62.4 ΔP =k<em>h</em>sg H= 12 0.433 𝑥 0.968 =28.63ft</p> Signup and view all the answers

<p>Same question BUT we have the level but not the dry leg</p> Signup and view all the answers

<p>Mechanical Springs = Located under each leg of a vessel or the vessel is suspended by them Load Cells = Convert a force such as tension, compression, pressure, or torque into an electrical signal Weight Method = Considered an indirect and non-invasive method Tare Weight = The empty vessel weight</p> Signup and view all the answers

<p>Load Cell = A type of transducer that converts a force into an electrical signal Single point Load cell = A type of load cell that is commonly used Indirect Method = A method in which weight is used to calculate the level for solids and liquids Content Weight = The weight of the vessel and its contents</p> Signup and view all the answers

<p>$Content Wt(lb) = Measured Wt (lb) – Tare Wt (lb)$ = Content Weight $Volume (cubic feet) = Density (lbs/ft^3) Volume (cubic feet)$ = Volume $Level (feet) = Surface Area (square feet) Area=πr^2$ = Level $Area=πr^2$ = Area</p> Signup and view all the answers

<p>Rotational Suppression Method = Typically used for granular or powered materials, direct, invasive, point measurement Nuclear Level Measurement = Based on the weakening of gamma radiation as it penetrates materials, indirect, non-invasive, continuous measurement Electronic Sensors = Ultrasonic Sensors: Ultrasonic sound waves are transmitted, and the time required for the return echo is measured. Radar Sensors: Similar in principle to ultrasonic, but uses high frequency radio waves instead of sound. Conductive Probes: Rods are suspended in an electrically conductive material and a circuit path will form between the rods. Capacitive Probes: A rod is suspended in non-conductive material to be measured and the capacitance between the rod and the vessel wall is measured Differential Pressure Method = Measures the difference in pressure between the top and bottom of a pressurized tank, indirect, invasive, continuous measurement</p> Signup and view all the answers

<p>$Area=10 ft^2$ = Content Wt (lb) = Measured Wt (lb) – Tare Wt (lb) $V=2000 lb/37 lbs/ft^3$ = Volume (cubic feet) = $V=2000 lb/37 lbs/ft^3$ $L = 5.405 ft$ = Level (feet) = $L = 5.405 ft^3$ $V = 2.36 ft^3$ = If we used Mercury instead of wheat, with a density of 848 lb/ft3, what would its height be.</p> Signup and view all the answers

<p>Content Weight (lbs) = The weight of the material being measured in the vessel Tare Weight (lb) = The empty weight of the vessel Measured Weight (lb) = The total weight of the vessel and its content Density (lbs/ft3) = The mass per unit volume of a substance</p> Signup and view all the answers

<p>Bubbler System = One of the oldest types of level measurement, used for liquid and fine powders Constant Differential Pressure Relay = A very accurate regulator used in the Bubbler System Load Cells = Alternative to Mechanical Springs, can be located at the base of the tank or above it Tare Weight = The empty weight of the vessel or tank, subtracted from the measured weight to get the content weight</p> Signup and view all the answers

<p>$968 = 12 psi \Delta P = Hl - LO$ = Equation for calculating the differential pressure in the Bubbler System $LO = 20psi - 12psi = 8psi$ = Equation for calculating the backpressure in the Bubbler System $27.72$ water is $1$ psi = Conversion factor used in the Bubbler System $\frac{1}{2}$ psi change can represent over $13.85$&quot; of level change = Relationship between pressure change and level change in the Bubbler System</p> Signup and view all the answers

<p>Advantages: Not affected by foaming, conductivity, solids. Reliable because only part in contact with process is a tube. Self clean, Can be used for many different types of processes, such as slurries, corrosive, acidic or radioactive. Cost effective and relatively easy to configure = Bubbler System Disadvantages: Essential to maintain a constant supply pressure. Hole in dip tube. Turbulent process will affect reading = Bubbler System Advantages: Direct measurement, accurate, simple to install and maintain. Independent of process conditions. Can be used for many processes. Can be used for both liquids and solids. Can be used in all types of vessels = Load Cells Disadvantages: High initial cost. Not suitable for high pressure or high temperature applications = Load Cells</p> Signup and view all the answers

<p>Differential Pressure Method = Method considered indirect and non-invasive Electronic Sensors = Type of level measurement that provides an output signal Mechanical Springs = Used under each leg of a vessel in the Weight Method Nuclear Level Measurement = Method used for measuring levels of liquids and fine powders</p> Signup and view all the answers