Preparing for Absence of Voltage Testing

Electrical Testing Safety – Part 1

Before you take a single measurement:

  • Will you be troubleshooting or testing for the absence of voltage?
  • What tools will you use to verify the energized or de-energized state?
  • What Personal Protective Equipment (PPE) will be required?

These are just a few of the questions that will be answered by Jim White, training director at Shermco Industries. Read the first in this two-part series on electrical testing safety.
Testing Safety – Part 1 » from Fluke

Posted in Electrical, Maintenance, Measurement, Safety, Troubleshooting | Leave a comment

Calibration Report Tool Released for Evaluation

The new E & I Tech CalReportTool is ready to download for evaluation (Demo version, Rev. 5/24/2013). See Revision History below for the latest bug fixes and new features. Check back here for the latest revision.

See CalReportTool Instructions for User instructions. If you would like to purchase a Working version after trying the Demo version, contact E & I Tech by e-mail at eandi.training@gmail.com.

Summary:

Most calibration documentation programs on the market are very costly and not easily customizable.  Some can be difficult to learn and modify if you’re not proficient with SQL databases and Crystal Reports. Simpler programs may only provide a few canned reports that cannot be modified.

E & I Tech CalReportTool is a low-cost yet customizable Calibration Report Tool for documenting Process Instrument Calibrations in the shop or the field. It’s based on the popular Microsoft Excel spreadsheet program used by most companies and is compatible with the free OpenOffice spreadsheet program.

CalReportTool allows for manual entry of your Calibration Data and automatic generation of professional-looking Calibration Reports with calculated results including % Error.

CalReportTool is ideal for small and medium plant workloads. It can be used for almost any process instrument including: pressure, temperature, flow, and level transmitters, transducers, signal converters and isolators, I/P and P/I converters, pressure and level gauges, temperature indicators, process indicators, analyzers, ADC’s, and DAC’s. It works for analog and for digital (Smart) transmitters.

View a Sample Report that shows Calibration Data formatted by the User.

Features:

  • Reports can be customized with your Company Name & Address and/or Logo.
  • Allows direct entry of Calibration Data without the need to record data on paper forms, reducing the chance for transcription errors.
  • Data fields for instrument information including, Manufacturer,  Serial number, Asset or Tag number, Location, Description, Input and Output Ranges, and Units.
  • Data fields for calibration information including Calibration Date, Calibration Technician’s name, up to three Calibration Reference Standards, Calibration Procedure name and Revision level, Process Tolerance in % of Span (% of Reading also available), optional Notes, Calibration Interval and Calibration Due Date.
  • Calibration data can be entered in mA for Process Transmitters (or optionally in V, mV, Ohms, Hz., counts, %, etc., or in Process Units).
  • Calibration % of Span (% Full Scale) Error is calculated and displayed as each calibration data point is entered allowing the User to determine if the instrument is in or out of tolerance during calibration. (see Calibration % Error Calculations)
  • Automatic calculation of Calibration Standard data (test) points from the Instrument range. This data can be overwritten by the User with custom or actual test point data (if the Standard test values are not the same as the nominal test values).
  • Comprehensive test data can be entered for upscale and downscale tests in steps from 0 to 100% of calibrated range. This allows for Linearity and Hysteresis testing. 25% steps are recommended for cost-effective linearity testing of analog devices and most other process instruments.
  • Up to 11 data points for various calibration schemes such as: 5-pt (50% steps) up-dn, 9-pt (25% steps) up-dn, 11-pt (20% steps) up-dn, 3-pt (50% steps) up, 5-pt (25% steps) up, 6-pt (20% steps) up, and 11-pt (10% steps) up.
  • 11-pt (10% steps) up-dn As-Found or As-Left reports can be done by renaming the As-Found and As-Left data tables “Increasing” and “Decreasing.” Two reports would be needed for both As-Found and As-Left data in that case.
  • Ability to clear As-Found or As-Left Instrument Data and calculations fields. This is useful if the As-Found and As-Left calibrations are done on different days or if only As-Found or As-left calibration data was taken. This prevents problems with the Calibration Error plot when there is only data for one series.
  • Automatic calculation of Instrument Output and Deviation in Process Units.
  • “F” in right margin next to a data table indicates a Failed Cal (Out of Tol.) point.
  • Second page of the report has an As-Found and As-Left Calibration Error plot for easy interpretation of % Error, Linearity, and Hysteresis.
  • The Error plot will include the number of data points entered in your data table and is automatically scaled for the instrument range and the maximum error.
  • Two full lines for As-Found (Before) and As-Left (After) Calibration Notes.
  • Fields for Calibration Technician and Supervisor approval names, or signatures, and dates.
  • Option for Barcode entry of Serial Number with a low-cost scanner.

Revision History:

4/24/2013, Calculation of High and Low Output Limits corrected.
4/25/2013, Added Failed Cal flag and text.
5/4/2013, Modified to allow for deleting As-Found or As-Left data when only one set of data is available.
5/6/2013, Modified to allow up to 11 data points for As-Found and for As-Left data.
5/24/2013, Improved Company Address fields to allow for 3 lines.

Known bugs:

None at this time:)

Future Tools:

  • Future App to print Calibration Stickers with Company Name or Logo, Cal Tech name, Cal Due Date, etc., with a low-cost label printer.
  • Future CalRecallTool for scheduling and tracking Calibration Recall.

More Information:

For more information on E & I Tech CalReportTool, contact E & I Tech by e-mail at eandi.training@gmail.com.

Comments & Suggestions:

Please leave your comments and suggestions with the Leave a Comment link below.

Rev. 12/30/2019

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Calibration % Error Calculations

The Accuracy for most Process Instruments is usually specified in % of Span or simply % Span. The calibration Span is defined as Upper Range Value (URV) minus Lower Range Value (LRV). For Zero-based instruments, % Span is also known as % of Full Scale (% FS). Note that some instruments may be specified in % of Reading or % of Reading + % of Span, so be careful.

The equation for % Span is:

% Span = ((INSTSTD) / Span) * 100

INST is the Instrument reading, or output, in engineering units.

STD is the value of the Calibration Standard (or Reference Standard) Instrument.

Span is the Instrument’s Upper Range Value – Lower Range Value (or simply the Upper Range Value for Zero-based ranges).

% Span should be calculated at every calibration test point from 0 to 100% of Span (3 point minimum, 5 or more points is better for checking linearity.

Note that the % Span will be negative for Instrument readings less than the Standard.

Example:

-20 to 120° F range

Instrument reads 49° F with a 50° F Standard for this example

Calculate % Span error at 50° F (midscale):

Span = URV – LRV = 120° F – (-20° F) = 140° F

% Span = ((INST – STD) / Span) * 100 = ((49° F – 50° F) / 140° F) * 100 = -0.71%

Conclusion:

Error Calculations can be tedious, let E & I Tech CalReportTool do them for you.

See also: Reading Accuracy Specifications by Transcat for information about reading and comparing accuracy specifications.

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