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<p>PHASE IFundamentals of Process Control</p> <p>1</p> <p>Agenda: Interpretation of transmitter specification Physical Functional Performance Dynamic performance</p> <p> Types of error Performance measurementRMT Sales Training - 05 /98 Phase I - Specification</p> <p>What Transmitter ???- we need to review Performance Requirements 4 SOURCES OF ERRORSensor interchangeability error OR Static pressure effect Drift over time (stability)</p> <p>2</p> <p>ERROR !</p> <p>Ambient temperature effectRMT Sales Training - 05 /98</p> <p>Reference accuracy</p> <p>Phase I - Specification</p> <p>Physical SpecificationsDescribe the Physical Make-Up of the Transmitter.</p> <p>3</p> <p> Materials of Construction: Housing materials, Process flange materials, Paints, bolts, etc. Process/Electrical Connection: Dimensions, thread types, and center-to-center dimensions of the process connections. Weight: Lists the weight of the instrument. Product Specific Physical Specifications: Example: Type of fill fluid, LCD options, Transient protector option, etc.</p> <p>RMT Sales Training - 05 /98</p> <p>Phase I - Specification</p> <p>Functional Specifications</p> <p>4</p> <p>Describes the Environment within which the transmitter can operator &amp; still meet its Performance Specification. Range Limits Upper Range Limit (URL) The highest quantity that a device can be adjusted to measure Lower Range Limit (LRL) The lowest quantity that a device can be adjusted to measure Upper Range Value (URV) 20 mA operating point (100% reading) Lower Range Value (LRV) 4 mA operating point (0% reading) Span URV - LRVRMT Sales Training - 05 /98 Phase I - Specification</p> <p>Functional SpecificationsExample of Range limits &amp; Spans:A Differential Pressure Transmitter LRL - 100 psi Transmitter Calibrated / Ranged: Sensor Limits 30 psi4 mA LRV 0% Reading Calibrated Span = 50 psi</p> <p>5</p> <p>URL 80 psi + 100 psi20 mA URV 100% Reading</p> <p>0</p> <p>Turndown ?URL / Cal. Span = 100 / 50RMT Sales Training - 05 /98</p> <p>2:1Phase I - Specification</p> <p>Functional Specifications Rangeability / Turndown Allowable range of spans through which errors are of an acceptable value Min. Span up to Span = URL Ex) Turndown = 10:1 &amp; URL = 500 psi Min. Span = URL / 10 = 50 psi Outputs The type of signal representing the process variable that is delivered by the transmitter Eg. 4-20 mA, 3-15 psi, Digital Service Describes the process that be measured. Eg. Liquid, gas, vapor</p> <p>6</p> <p>RMT Sales Training - 05 /98</p> <p>Phase I - Specification</p> <p>Functional Specifications Hazardous Location Describes the types of hazardous location that the transmitter is certified for use within. Eg. Class 1, Div 1and 2, Groups B,C Approvals Hazardous Area Zone 0 Zone 1 Zone 2 Weather proof IP65 / 66 IP67 / 68 Risk of FIRE &amp; EXPLOSION High Intermediate Occasional</p> <p>7</p> <p>Level of INGRESS PROTECTION 1st digits 6 represent Dust Tight. 2nd digits represent level of protection against water. The higher the value the the better the level of protection.Phase I - Specification</p> <p>RMT Sales Training - 05 /98</p> <p>Functional SpecificationsDanger of FIRE and EXPLOSION in HAZARDOUS AREAS Zone Safety approach Letter0 Intrinsically Safe Electronics safe Flameproof Explosion retained Flame quenched I</p> <p>8</p> <p>Code1 9</p> <p>AuthorityCENELEC (Europe)</p> <p>E</p> <p>5</p> <p>1</p> <p>FM (USA)</p> <p>2</p> <p>Non Incendive No arcs,sparks or hot surfaces</p> <p>N</p> <p>6</p> <p>CSA (Canada)</p> <p>RMT Sales Training - 05 /98</p> <p>Phase I - Specification</p> <p>Functional SpecificationExamples of Approvals for Transmitters SST Certification Tag Provided Explosion Proof E5 (FM) E8 (CENELEC / CESI) Intrinsic Safety I1 (BASEEFA / CENELEC) Non-Incendive N1 (BASEEFA / CENELEC) Non-Incendive + Intrinsic Safety I5 (FM) Explosion Proof + Intrinsic Safety C6 (CSA) K5 (FM) K8 ( FM + CSA) K6 (CSA = CENELEC)RMT Sales Training - 05 /98</p> <p>9</p> <p>Phase I - Specification</p> <p>Functional Specifications Failure Mode Alarm If self-diagnosis detects a gross transmitter failure, the analog signal will be driven to low output /high output to alert the user</p> <p>10</p> <p>Process Variable Out of Range 3.9 mA 3.8 Hardware Alarm 21.75 4 Normal Operating Range 20 20.8</p> <p>RMT Sales Training - 05 /98</p> <p>Phase I - Specification</p> <p>Functional Specifications Power Supply Describes the power that is required to operate the transmitter which will coincide with the output selected. At no load min. voltage is 12 V dc The max. voltage should not exceed 45 V dc Load limitation The maximum load that can be present in the loop for the transmitter to operate over its full output range for a given power supply. At voltage Vs : RL is the max. load possibleRMT Sales Training - 05 /98</p> <p>11</p> <p>Load</p> <p>Voltage</p> <p>Phase I - Specification</p> <p>Functional SpecificationsPressure Limits Static Pressure Limits Level of static(line) pressure that a transmitter can be exposed to in which the transmitter will function within specifications Overpressure Limits Level to which only one side of a pressure transmitter can be exposed to without causing damage Proof (burst) pressure Pressure to which transmitter can retain fluid without flying parts</p> <p>12</p> <p>RMT Sales Training - 05 /98</p> <p>Phase I - Specification</p> <p>QuizExample #2 1151DP4S (URL = 150 inH2O, min span = URL/15 10 inH2 Min. Span= _______O 15:1 Max. Turndown = __________ 3051CD3 (Range: 0 -10 to 0 - 1000 inH2O)</p> <p>13</p> <p>Min Span 10 inH2O _______ Max. Turndow = __________ 100:1RMT Sales Training - 05 /98 Phase I - Specification</p> <p>Performance Specifications</p> <p>14</p> <p>Quantify Uncertainty of a Measurement as a Function of Changing Ambient &amp; Process Conditions. Reference Accuracy Defines maximum error at reference conditions</p> <p>Zero-based: 14.73 psia, 68 deg F. May have limits on material types Includes effects of linearity, repeatability, hysteresis Typically expressed as a % of calibrated span</p> <p> Ways to express reference accuracy:</p> <p> % of URL % of span % of readingRMT Sales Training - 05 /98</p> <p>Commonly used in Transmitters</p> <p>Phase I - Specification</p> <p>Performance Specifications Transmitters are factory calibrated at room temperature. If transmitter operates at a different ambient temperature, the electronics perform differently. The change in performance can create an error in the measurement. This error is the Ambient Temperature Effect</p> <p>15</p> <p> Zero Temperature Effects Expressed as a % of URL per some T from standard conditions Span Temperature Effects Expressed as a % of Calibrated Span per some T from standard conditions.RMT Sales Training - 05 /98 Phase I - Specification</p> <p>Performance Specifications Static Pressure Effects The effect on transmitter zero and span due to the application of static (line) pressure</p> <p>16</p> <p> Applies to differential pressure transmitters only. Zero LP Effect: Expressed as % of URL per change in static pressure Span LP Effect: Expressed as % of Calibrated Span change in static pressure Same Flow RateAt different Line Pressure </p> <p>50 psi 100 psi 500 psi 1000 psi</p> <p>Span = 20 psi</p> <p>30 psi 80 psi 480 psi 980 psi</p> <p>However at higher line pressure the sensor is subject to higher stress &amp; therefore may induced error in registering the DPRMT Sales Training - 05 /98 Phase I - Specification</p> <p>Performance Specifications</p> <p>17</p> <p>Stability Change in output given a fixed input as a function of TIME. Determines calibration frequencies. Units of uncertainty are dependent on product type.All transmitters will drift over time , compounding error in the point measurement</p> <p> Vibration Effect The effect upon output is solely due to the vibratory environment to which the transmitter is subjected. Power Supply Effect If a transmitter is operated at a different voltage in the field, then it was calibrated with on the bench, then variations in output (for the same input) can occur.RMT Sales Training - 05 /98 Phase I - Specification</p> <p>Performance Specifications RFI/EMI Effects Output change as a result of radio or electromagnetic interference. Potential sources of interference: Motors, Radios Mounting position Difference in output when a transmitter is mounted in a position different to which it was calibrated. Load Effect If the total loop should alter, then the output of the transmitter (for the same process input) may be effected Linearity Maximum deviation from a Straight Line.RMT Sales Training - 05 /98</p> <p>18</p> <p>Phase I - Specification</p> <p>Performance Specifications Repeatability: Ability to reproduce output reading when same input is applied under the same conditions, and in the same direction. Hysteresis: The maximum difference in output at any input value, when the value is approached first with increasing then decreasing input.</p> <p>19</p> <p> Reproducibility: The closeness of agreement among repeated measurements of the output for the same value of the input under the same operating conditions over a period of time, approaching from both directions. It includes hysteresis, drift and repeatability.RMT Sales Training - 05 /98 Phase I - Specification</p> <p>Performance SpecificationsExample #3Assuming an input of 80 inH2O: Pressure Transmitters URL = 300 inH2O Calibration: 0-200 inH2O What is the maximum error (%) at reading ? Acc = 0.1% of URL 0.001 x 300 = 0.3 inH2O (0.3 / 80) x 100% = 0.375% Accuracy as specified (0.1% of span) 0.001 x 200 = 0.2 inH2O</p> <p>20</p> <p>(0.2 / 80) x 100% = 0.25%</p> <p> Accuracy = 0.1% of reading 0.1%RMT Sales Training - 05 /98 Phase I - Specification</p> <p>Performance SpecificationsExample #4Given Zero Error = 0.25% of URL for 2,000 psi &amp; Span Error correctable to 0.25% of reading per 1,000 psi What is the maximum LP error (%) of an 1151DP4S (URL = 150 inH2O) at 1500 psi static pressure, calibrated 0 to 100 inH2O, measuring 60 inH2O? (0.0025 x 150 x 0.75) + (0.0025 x 60 x 1.5) =0.58 psig Zero error span error total error</p> <p>21</p> <p>What is the maximum LP error (%) of an 1151GP8S measuring 1000 psig? N.ARMT Sales Training - 05 /98 Phase I - Specification</p> <p>Performance SpecificationsExample #5Given Ambient Temperature Effect per 50F : (0.0125% URL + 0.0625% Span) spans from 1:1 to 10:1 (0.025% URL + 0.125% Span) spans from 10:1 to 100:1 What is temperature error (%), expressed in psig, of a 3051CG5 (URL = 2000 psig) , calibrated 0 to 1000 psig in factory at 68F, measuring 500 psig, at 168 deg F. (0.000125 x 2000) + (0.000625 x 1000) = 0.65 psig 0.65 psig x 2 = 1.3 psig What is the minimum amount of error (%) that could be achieved without re-zeroing at temperature? 0 psig</p> <p>22</p> <p>2:1</p> <p>100F</p> <p> 2:1</p> <p>RMT Sales Training - 05 /98</p> <p>Phase I - Specification</p> <p>Dynamic PerformanceResponse Time DefinitionsDeadtime Time</p> <p>23</p> <p>(Td): The time before output starts to change.</p> <p>Constant (Tc): The time necessary (after deadtime) for output to reach 63.2% of its final value.Total</p> <p>Response Time (T63): Deadtime (Td) plus one Time Constant (Tc) Faster Responding Sensor (Tc)</p> <p> Transducer response time Faster Update Rate (Td)</p> <p>Td</p> <p>Tc</p> <p> Signal conversion time (eg. A/D modem) Optimized Software / Processing (Td)63.2%</p> <p>}</p> <p> Micro-processing time Minimal Filtering (Tc)</p> <p> adding a delay time Total Response Time (T63)RMT Sales Training - 05 /98</p> <p>Damping0</p> <p>T63Time</p> <p>Phase I - Specification</p> <p>Different Types of Errors4-20 mA OUTPUT 4-20 mA OUTPUT 4-20 mA OUTPUTIdeal Span 0 to 100 inH2O Input</p> <p>24</p> <p> Zero-Error Fixed offset betweentrue and measured value.4-20 mA OUTPUT 4-20 mA OUTPUT 4-20 mA OUTPUTIdeal Span 0 to 100 inH2O Input</p> <p> Span-Error Difference between calibrated and ideal span.</p> <p> Total-Error Zero Error plus Span Error.RMT Sales Training - 05 /98 Phase I - Specification</p> <p>Different Types of Errors Turndown Error Arises when a span less than the Transmitters full span is used. The smaller the calibrated span, the greater the errors over the span. Turndown Factor 4 : 1 4095 : 1023 Resolution &lt; 0.1% 8 4095 : : 1 5110</p> <p>25</p> <p>Sensor Curve F</p> <p>For example: 12 bits Register represent full sensor range</p> <p>PURL</p> <p>Resolution = 1/4095 &lt; 0.1% Capacitance to Digital converter (A/D)Phase I - Specification</p> <p>Resolution &gt; 0.1%RMT Sales Training - 05 /98</p> <p>8:1</p> <p>4:1</p> <p>Performance Measurement</p> <p>26</p> <p>Total probable error (TPE) analysis provides a more accurate picture of how a transmitter can be expected to perform under specific conditions or changes in conditions. The Root Sum Square(RSS) method determines the TPE by summing the squares of individual error components, and then taking the square root of the total. Up = (accuracy2 + temp eff2 + (...eff)2)1/2 where Up = total uncertainty (TPE) Worse Case Error is the sum of individual error components. This error is unlikely to occur, since all the effects may not take place at the same time.</p> <p>RMT Sales Training - 05 /98</p> <p>Phase I - Specification</p> <p>Total Probable ErrorExample #6Given: Accuracy = +/-0.1% of span Total Temperature Effects = +/-0.5% of span LP Effects = +/-0.3% of span Power Supply Effect = +/- 0.010% of span</p> <p>27</p> <p>What is the TPE in (express in psig) if the calibrated span is 3.61 psig?</p> <p>(0.12 + 0.52 + 0.32 + 0.012) = 0.59% 0.0059 x 3.61 psig =RMT Sales Training - 05 /98</p> <p>0.02 psigPhase I - Specification</p> <p>Test</p> <p>28</p> <p>Select the appropriate term for the following definitions: (A) Damping (B) Reference Accuracy (C) Dead-time (D) Time-constant (E) Response time (F) Repeatability (G) Stability (H) Span error (I) Turndown error (J) Zero error 1. An error occurred when the transmitter is used at a span other than its full span. 2. Fixed offset between true &amp; measured value. 3. Time necessary for analog output to reach 63.2% of its final value.RMT Sales Training - 05 /98</p> <p>[ [</p> <p>] ]</p> <p>[</p> <p>]Phase I - Specification</p> <p>Test4. Deviation in measurement for the same input approaching from one direction. [ ]</p> <p>29</p> <p>5. Electronic delay circuit to increase transmitters response time.6. Limits of error at standard reference conditions.</p> <p>[ [</p> <p>] ] ] ] ] ]</p> <p>7. Time before transducers output starts to change. [ 8. Transmitters drift over time. 9. Dead-time + Time constant. 10. Drift in transmitters calibrated range.RMT Sales Training - 05 /98</p> <p>[ [ [</p> <p>Phase I - Specification</p> <p>Answer SheetSpecifications FundamentalEnter the answers for the test given in this module and sent one copy to the RMT A/P Trainer in Singapore . Attention to RMT Trainer at Fax : (65) 7708000 or (65) 7770947 or (65) 7770743 E-Mail : mohd.rafi@frco.comName: Company: Q1 Q2 Q3 Q4 Q5 Marks: /10 Title: Date: Q6 Q7 Q8 Q9 Q10 Marks (%):</p> <p>30</p> <p>RMT Trainer will feedback to you the result &amp; solutionRMT Sales Training - 05 /98 Phase I - Specification</p>

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