Emerson 4500 manual Determining Calibration Frequency, Calculate total probable error TPE

Page 44

Rosemount 4500

Reference Manual

00809-0100-4027, Rev AA December 2005

Determining Calibration Frequency

Calibration frequency can vary greatly depending on the application, performance requirements, and process conditions. Use the following procedure to determine calibration frequency that meets the needs of your application.

1.Determine the performance required for your application.

2.Determine the operating conditions.

3.Calculate the Total Probable Error (TPE).

4.Calculate the stability per month.

5.Calculate the calibration frequency.

Sample Calculation

Step 1: Determine the performance required for your application.

Required Performance:0.60% of span

Step 2: Determine the operating conditions.

Transmitter:

4500, Range 2 (URL=150 psi),

Calibrated Span:

100 psi

Ambient Temperature Change:

± 50 °F

Step 3: Calculate total probable error (TPE).

TPE =

( ReferenceAccuracy)2 + (TemperatureEffect)2 = 0.27% of span

Where:

 

 

 

 

 

 

Reference Accuracy =

± 0.15% of span

 

Ambient Temperature Effect =

 

 

 

 

±

0.2%CS +

0.02% URL ⎞

per 50 °F =

±0.23% of span

 

-------------------------------span

 

 

 

 

 

Step 4: Calculate the stability per month.

Stability = ±

--------------------------0.1% URL

(% of span for 3 years) = ±0.0042% of span

 

span

 

Step 5: Calculate calibration frequency.

Cal. Freq. = (---------------------------------------------------------------Req. Performance TPE)-

= (--------------------------------------0.6%0.27%)- = 78.6 months

Stability per Month

0.0042%

4-4

Image 44
Contents Reference Manual Page Rosemount 4500 Hygienic Pressure Transmitter Page Table of Contents Operation Maintenance SectionUsing this Manual Section IntroductionService Support Section Installation Overview Safety MessagesEnvironmental ConsiderationsGeneral Hart Installation Flowchart Installation Procedures Mount the TransmitterSet Switches LCD Switches LOI SwitchesConfigure Alarm Direction AMSConnect Wiring and Power Up Hart Terminal BlocksInstalling the LCD Meter GroundingSection Configuration Setting the Loop to Manual Commissioning on the Bench with HartWiring Diagrams Hart Communicator Menu TreeFast Key Sequence Function Hart Fast Key SequenceReview Configuration Data Process Variables Sensor TemperatureCheck Output Rerange Basic SetupSet Process Variable Units Fast Keys 3, 1 Damping LCD DisplayDetailed Setup Failure Mode Alarm and SaturationAlarm and Saturation Level Configuration Alarm and Saturation Levels for Burst Mode Alarm and Saturation Values for Multidrop ModeAlarm Level Verification Process Alerts Scaled Variable Configuration Rosemount Re-mapping Transmitter Test Sensor Temperature UnitDiagnostics Service Loop Test Saving, Recalling, Cloning Configuration Data Advanced Functions for Hart ProtocolRosemount Burst Mode Multidrop Communication Polling a Multidropped Transmitter Changing a Transmitter AddressCommunicating with a Multidropped Transmitter Operation and Maintenance Overview Calibration for Hart ProtocolCalibration Overview Transmitter Data Flow with Calibration Options Calculate total probable error TPE Determining Calibration FrequencyChoosing a Trim Procedure Sensor Trim Zero Trim Full TrimRecall Factory Trim Recall Factory Trim- Sensor Trim Recall Factory Trim- Analog Output Analog Output Trim Digital-to-Analog TrimDigital-to-Analog Trim Using Other Scale Diagnostic Messages Fail ModuleNonpv Limit Stuck KEY Troubleshooting Symptom Corrective Actions Appendix a Reference Data SpecificationsPerformance Specifications Functional Specifications 00809-0100-4027, Rev AA December Range and Sensor LimitsRosemount Physical Specifications Dimensional Drawings 11/2 inch Tri-Clamp ModuleInch Tri-Clamp Module Fractional Line Fitting Module Ordering Information Code Process Connection StyleAppendix B Product Certificates Hazardous Locations Certifications North American CertificationsRosemount Rosemount Index Index-2 Page ¢00809-0100-4027 ¤