Load Cell Compatibility Worksheet User's Guide
Contents
1. 2 or mid range or interval and be entered in the same units as Max of the device 3 range or interval required for multiple range or multi interval device This value must equal Max amp e of the 3 or largest range or interval and be entered in the same units as Max of the device This worksheet is only capable of dealing with a maximum of three ranges or intervals If more are required please contact your Regional Gravimetric Specialists for more information D Load Cell s 1 3 Accuracy Class Enter the Accuracy Class for the load cell This should be taken from the Notice of Approval NTEP Certificate of Conformance or OIML Certificate of Conformity when possible Class may be OIML or NTEP The rest of the parameters must be applicable to the Class of load cell chosen in this step Load Cell Maximum Capacity Emax Manufacturer s rating for maximum load cell capacity Must be entered in the same units as LRE Max above Load Cell Minimum Capacity Emin Manufacturer s rating for minimum load cell capacity This is the smallest load that may be applied to a load cell without exceeding the maximum permissible error mpe for the cell The load cell is not designed to be used below this capacity and must be pre loaded beyond this value in use Must be entered in the same units as LRE Max above This value may be equal to zero 0 in some cases Load Cell Safe Limit lim For now this is a non mandatory field Man2. These are intended for non trade applications only Certain parameters will not be monitored by Measurement Canada however it is suggested that OIML amp NTEP requirements for selecting suitable load cells be followed whenever possible These non monitored items include cable length area and resistance OIML condensating classifications and NTEP S amp M designations OIML NTEP MC NAWDS Min Max e A I I 50 000 B I II 100 100 000 II e gt 0 1g 5 000 100 000 C III III 100 10 000 III e gt 5g 500 10 000 HIL IHD 2 000 10 000 D mI II 100 1 0007 gt Class INHD should be limited to 10 000 divisions to comply with load cell restrictions 4 Class HII should be limited to 1 000 divisions to comply with load cell restrictions Measurement Canada Page 18 01 Jan 2011 Load Cell Approvals LC Compatibility Worksheet instructions OIML Load Cell http oiml org certificates OIML LOAD CELL MARKINGS Load Cell Verification Intervals n Humidity Class Special temperature limits Stated in units of 1000 NH Low High in C eg 3 3000 CH 1 5 1500 SH Only required if range is other than Not applicable to MC 10 C to 40 C C3 NH 5 30 Accuracy Class Loading Type a A Class A Tension ge B Class B z B Class B OIML lass Compression S amp D Class D L G tor Beam bending or shear CEprance pe Universal Measu
3. currently monitored by Measurement Canada 10 Length of additional cable between Load Cells and Indicator per wire cross section in m mm The length of additional cable between the load cell and the indicator should be accounted for Additionally load cell cable supplied with the approved load cell should not be cut to suit the installation The resistance of the cable is integral to the calibration parameters of the load cell The following equation should be satisfied L A lt L A max This parameter is not currently monitored by Measurement Canada Measurement Canada Page 17 01 Jan 2011 Load Cell Approvals LC Compatibility Worksheet instructions How to Read a Load Cell Measurement Canada has chosen to accept NTEP and OIML approved load cells It is up to the scale manufacturer to decide which will be used Once a selection is made the parameters for that approval must be used You cannot mix and match parameters between the two approvals For purposes of ensuring that a load cell is suitable for use the following are deemed to be equivalent e OIML Class A NTEP Class I suitable for use in MC NAWDS Class I devices e OIML Class B NTEP Class II suitable for use in MC NAWDS Class II devices e OIML Class C NTEP Class IT IIL suitable for use in MC NAWDS Class IW INHD devices e OIML Class D NTEP Class III suitable for use in MC NAWDS Class III devices e Some manufacturers may use other Class designators
4. no legal authority Her Majesty makes no guarantees representations or warranties respecting the Worksheet either express or implied arising by law or otherwise including but not limited to effectiveness completeness or accuracy or fitness for a particular purpose Measurement Canada Page 5 01 Jan 2011 Load Cell Approvals LC Compatibility Worksheet instructions Sa Majest n est aucunement responsable des erreurs des omissions ou des nonc s trompeurs d coulant de l utilisation de la feuille de calcul automatis e Les donn es les renseignements ou les r sultats obtenus lors de l utilisation de la feuille de calcul n ont aucun pouvoir l gal Sa Majest ne formule aucune garantie ni r clamation relativement la feuille de calcul qu elle soit expresse ou implicite d coulant des lois ou autrement notamment quant l efficacit l int gralit l exactitude ou au caract re appropri de la feuille de calcul dans un but particulier 3 Her Majesty shall not be liable in respect of any claim demand or action alleging any loss injury or damages direct or indirect which may be attributable to the reliance on and use of the Automated Worksheet Sa Majest n engage nullement sa responsabilit l gard de toute r clamation revendication ou poursuite qui se fonde sur une perte des blessures ou des dommages directs ou indirects pouvant d couler du fait que l utilisateur a utilis la feuille de calcul
5. receivers which allow for only minimal eccentric loading hopper or tank or with one single point load cell b 20 Max for other conventional weighing devices c 50 Max for On Board weighing devices overhead rail scales etc d 50 Max for multi platform weighing devices This value is to be determined by the scale company responsible for configuring the device The value may be set to zero 0 if it is not required 9 Non Uniform Distribution Factor NUD This value is in terms of mass and is calculated as Max x NUD Do not enter a value in this field it is calculated automatically 10 Positive Additive Tare range T Enter the maximum amount of Positive Tare the device is capable of applying to the weight display Enter 0 if not applicable This value is used to address the additional load placed upon the LRE when tare is in use 11 Temperature Limits for the Weighing Element This should be a range of 10 to 40 degrees Celsius unless otherwise stated in the NOA for the device These values must be entered in degrees Celsius C 12 Load Cell cable length L For now this is a non mandatory field It is suggested that the length of the cable in metres supplied with the load cells be entered in this field It is further recommended that the supplied load cell cables not be cut to suit the application 13 Cross section of the wire in the load cell cable A For now this is a non mandatory field It is su
6. templates will be displayed and the appropriate one may be chosen In this way you will not have to worry about corrupting the original template and the automated features will work as expected Occasionally security settings may prevent the application from running properly If prompted please allow the application to run on your system Security settings may be changed in Excel 2003 through the Tools gt Macro gt Security gt Security Level tab Choosing Medium Security will prompt you to allow the application to run Default template folder Windows XP drive Documents and Settings user name A pplication Data Microsoft Templates Default template folder Windows Vista and Windows 7 drive Users user name AppData Roaming Microsoft Templates The user should always ensure that they are using the latest version of the template that is available from Measurement Canada Although you may use the Worksheet XLS use of the Template XLT is preferred Properly using a template file will ensure that you never inadvertently corrupt the master template file The template has not been tested on an Apple Mac Computer Measurement Canada Page 1 01 Jan 2011 Load Cell Approvals LC Compatibility Worksheet instructions Icons x G Translate Delete Print Info Language The language of the template may be toggled using the translate button at the top left of the data entry screen The language may also be toggled from the Aut
7. type selected in the check box on the first Data sheet The manual worksheet always shows all fields but the highlighted fields which must be completed will also change according to this selection 5 Maximum Capacity of the load cells must be compatible with Max of the Indicator This seems like a simple requirement but the calculations are somewhat complex In order to ensure that the load cell capacity Emax is suitable for use with the indicator we must calculate a correction factor Q Q is used to account for possible eccentric loading NUD dead load of the weighing element DL initial zero setting range IZSR and additive tare T Q Max DL IZSR NUD T Max Once this has been done the maximum capacity of the load cell Emax must satisfy the condition Emax gt Qx Max x R N 6 a Maximum number of Verification Scale Intervals of the Load Cell and the Indicator The chosen load cell must be approved for no less than the number of verification scale intervals of the device as configured nic gt Max e For a multi interval or multiple range Indicating Element this applies to any individual weighing range or partial weighing range nyc gt Max ei b Minimum Dead Load output return of the load cell and smallest verification scale interval of a multi interval weighing device On a Multi Interval device the minimum dead load output return must be sufficient for each interval This can be calculate
8. 0 degrees Celsius unless otherwise stated in the NOA for the device These values must be entered in degrees Celsius C 9 Fraction of the maximum permissible error mpe for the indicating elements Pina Unless otherwise specified in the NOA this value shall be 0 7 This field has been disabled in this version of the worksheet 10 LC Cable connection For now this is a non mandatory field This value must be either 4 or 6 wires Enter 4 if there are no sense lines if the sense lines are tied to the excitation lines at the indicator or if the sense lines are simply not being used 6 should only be entered when the sense lines are taken all the way back to the load cells 6 wire installations are recommended 11 Maximum load cell cable length wire cross section L A max For now this is a non mandatory field This value may be obtained from the indicating element manufacturer Measurement Canada Page 10 01 Jan 2011 Load Cell Approvals LC Compatibility Worksheet instructions C Configuration Single Range automatically entered for single range device Multiple Range or Multi Interval Device 1 range or interval required for multiple range or multi interval device This value must equal Max amp e of the 1 or smallest range or interval and be entered in the same units as Max of the device 2 range or interval required for multiple range or multi interval device This value must equal Max amp e of the
9. Load Cell Approvals LC Compatibility Worksheet instructions Load Cell Compatibility Worksheet User s Guide Ver 1 00 01 Jan 2011 The Excel Worksheet Template LC_Compatibility xlt has been prepared to assist the user in ensuring that a device meets the Measurement Canada guidelines for use of appropriate Approved Load Cells Approved Load Cells are only mandatory in those devices where the requirement is noted in the Notice of Approval NOA The use of Approved and compatible load cells is recommended in all devices Use of the worksheets electronic or manual is not mandatory but is recommended to ensure the selected load cell is suitable for use in the device Completion of the worksheet will prove that all requirements have been met It is further recommended that a copy of the worksheet be kept on file for each scale configuration Use of the Template To use the worksheet template you must be running Microsoft Excel ver 2003 SP3 or later on a PC Some features may not be supported by previous versions of the application The manual worksheet may be used instead of the electronic version but care must be taken to ensure the calculations are completed properly Additional copies of the template and or the worksheets may be obtained directly from Measurement Canada The template XLT file should be installed in your Microsoft Excel Template folder The template is then selected through the Excel File gt New menu The available
10. ations shall be satisfied U gt U min AU gt AU min The minimum input voltage for the indicator U with an unloaded weighing element is calculated as follows U C x Vexc X R x DL Emax X N The signal per verification scale interval AU is calculated as follows Measurement Canada Page 16 01 Jan 2011 Load Cell Approvals LC Compatibility Worksheet instructions Au G x Uac X x e Es N Uexe load cell excitation voltage V B 3 Umin minimum signal input voltage for the indicator mV B 4 AUmin minimum signal input voltage per verification scale interval uV B 5 UMRmin Measuring range minimum signal voltage mV UMRmax Measuring range maximum signal voltage mV Emax load cell maximum capacity D 2 rated load cell output in mV V D 6 verification scale interval A 3 number of load cells A 4 reduction ratio A 5 AZ iO 9 Minimum signal input voltage for the Indicating Element indicator and minimum input voltage per Verification Scale Interval e compared to the actual output of the Load Cells The load cell impedance Ric should be matched to the indicator This may be verified by ensuring that the resistance of the load cell number of load cells in use falls within the rated impedance range as specified by the indictor manufacturer Rimin lt Ric N lt Rimax Rimin minimum load cell impedance Q Rimax maximum load cell impedance Q This parameter is not
11. automatis e ou s y est fi Measurement Canada Page 6 01 Jan 2011 Load Cell Approvals LC Compatibility Worksheet instructions Parameters A Weighing or Load Receiving Element LRE l Accuracy Class Enter the Accuracy Class for the Weighing Element This must be a NAWDS approved Class and should be taken from the NOA when possible The Class entered in this field must reflect the device configuration Entering any other Class in this field is not acceptable In order to ensure data integrity the device Class should be selected from the drop down list Maximum Capacity Max Enter the Max or capacity of the device as configured In the case of a multiple range or multi interval device the Max for largest range or interval shall be entered in this field Units Select the appropriate units kg or lb for the data The units used here must be used throughout the rest of the sheet when entering mass You will have to select the units for Max All other units will be updated according to the units selected All data must be entered in the appropriate units for the sheet to function correctly Verification Scale Interval e Enter the interval size of the device as configured Interval size must be entered in the same units as Max In the case of a multiple range or multi interval device the e for largest range or interval shall be entered in this field Number of Load Cells N Enter the number of load cells used in th
12. d using the variable Z and ensuring that Z is not less than Max ei Z Emax 2 x DR Measurement Canada Page 15 01 Jan 2011 Load Cell Approvals LC Compatibility Worksheet instructions Z gt Max ei or nyc gt Max e c Minimum Dead Load output return of the load cell and smallest verification scale interval of a multiple range weighing device On a Multiple Range device where the same load cells are used for more than one range the minimum dead load output return of the load cell shall satisfy the equation Z gt 0 4 x Max e1 or nic 0 4 x Max e d Actual dead load of the load receptor compared to the minimum dead load of the load cells in kg In order to ensure that the cells are only used within the acceptable range we must ensure that the minimum dead load has been applied to the load cells The following equation must be satisfied DL x R N Emin 7 Compatibility between Verification Scale Interval e of the Weighing Device and minimum Load Cell interval in kg The minimum load cell interval Vmin must be appropriate for the configured verification scale interval e of the device V min Emax Y Vin Se xR N 8 Minimum signal input voltage for the Indicating Element indicator and minimum input voltage per Verification Scale Interval e compared to the actual output of the Load Cells In order to ensure that the load cell is an electrical match to the indicator the following equ
13. e load receiving element LRE If two or more LREs are used together each should be evaluated separately Most electro mechanical conversions use a single load cell In all cases there must be at least 1 load cell entered for the sheet to function correctly Reduction Ratio R Reduction Ratio is 1 for full electronic devices with no levers If there are levers then the reduction ration must be calculated The proper calculation is Reduction ratio force on load cell force on LRE 1 scale multiple Note Reduction Ratio is the inverse of the Scale Multiple Deadload DL Enter the weight of the LRE You must use the same units as used for Max above Initial Zero Setting Range IZSR You must calculate the range that the IZSR will function over and enter this value here The entry must be in terms of mass Measurement Canada Page 7 01 Jan 2011 Load Cell Approvals LC Compatibility Worksheet instructions not percentage This is the maximum amount of Initial Zero the device is capable of applying 8 Non Uniform Distribution Factor NUD NUD is a factor in percentage used to increase the required capacity of the load cells to account for such things as off center loading This factor is to be determined by the scale manufacturer and may be assumed to be zero 0 if appropriate The following values are recommended but not mandatory a 0 Max for devices with lever work and one load cell or with load
14. ents Emax Care must be taken to ensure that the correct units lb or kg are used The rated Cell Output C is 3 0491 mv V In this case the actual value is indicated and may be used in the worksheet In many cases the nominal value 3 mv V may be all that is indicated In the case of multiple load cells the nominal value may have to be chosen The remaining required information should be available on the Certificate that accompanies the load cell Search NTEP Certificates of Conformance at http www ncwm net ntep index cfm fuseaction search Measurement Canada Page 20 01 Jan 2011 Load Cell Approvals LC Compatibility Worksheet instructions Use of the Worksheet Any questions or concerns with the manual worksheet or the Excel template should be directed to your Regional Gravimetric Specialist for resolution Luciano Burtini Senior Program Officer Gravimetric Agent de programme principal Gravimetric Program Development Directorate D veloppement de programme Measurement Canada Mesures Canada Industry Canada Industrie Canada 151 Tunney s Pasture Driveway 151 all e du parc Tunney Ottawa ON K1A 0C9 email courriel luciano burtini ic gc ca Telephone T l phone 250 862 6557 Facsimile T l copieur 250 712 4215 Teletypewriter T l imprimeur 866 694 8389 Government of Canada Gouvernement du Canada Measurement Canada Page 21 01 Jan 2011
15. ggested that the cross sectional area in mm of one conductor within the load cell cable be entered in this field This information is usually available on the LC certificate or from the table below Measurement Canada Page 8 01 Jan 2011 LC Compatibility Worksheet instructions Load Cell Approvals AWG inches millimetres area mm 10 0 1019 2 59 5 26 11 0 0907 2 30 4 17 12 0 0808 2 05 3 31 13 0 0720 1 83 2 63 14 0 0641 1 63 2 08 15 0 0571 1 45 1 65 16 0 0508 1 29 1 31 17 0 0453 1 15 1 04 18 0 0403 1 02 0 82 19 0 0359 0 91 0 65 20 0 0320 0 81 0 52 14 Fraction of the maximum permissible error mpe for the connecting elements Pcon Unless otherwise specified in the NOA this value shall be 0 5 This field has been disabled in this version of the worksheet 15 Number of Divisions n This is a calculated field and must not be changed B Indi l cator Ind n Max e Accuracy Class Enter the Accuracy Class for the Indicating Element This must be a NAWDS approved Class and should be taken from the NOA when possible The Class entered in this field must reflect the device configuration Entering any other Class in this field is not acceptable Maximum Number of scale intervals nina Enter the maximum number of intervals that the indicating element has been approved for This information shall Measurement Canada Page 9 01 Jan 2011 Load Cell A
16. ice Currently Measurement Canada allows 0 7 x LOE when evaluating each component of a device This practice may be subject to change in the future in order to allow other error distributions Until changes are implemented only default values shall be used The default values are e 0 25 0 5 for the Weighing Element Peon e 0 25 0 5 for the Load Cell pic e 0 49 0 7 for the Indicating Element pina The values for the weighing element and the load cell combined are equal to 0 5 0 7 for the complete weighing element including load cells If evaluated separately the complete weighing element will be allotted 0 7 x LOE Any manufacturer wishing to change the distribution of errors should discuss this with the mass approval laboratory or their local Gravimetric Specialist 4 Maximum number of Verification Scale Intervals e of the Indicator and the Weighing Element For each indicator the maximum number of verification scale intervals ning shall not be less than the number of verification scale intervals n of the weighing element Measurement Canada Page 14 01 Jan 2011 Load Cell Approvals LC Compatibility Worksheet instructions Ning 2 N For a multi interval or multiple range Indicating Element this applies to any individual weighing range or partial weighing range Ninad gt Ni The automatic worksheet will change format to reflect single range multiple range or multi interval depending upon the device
17. ility Worksheet instructions Other Features Info Your Data screen may include an Info button Selecting this button will bring up a screen with user and application information This information may be useful to Measurement Canada when attempting to troubleshoot an issue with the worksheet Also on this screen may be an eMail button Selecting this button will email the worksheet to Measurement Canada for review This should be selected only if you are encountering an issue with the worksheet Many email systems will not allow automated emails without confirmation from the user If presented with a warning from your computer you must agree to allow the email to proceed or it will be discarded before being sent All emails currently go to luciano burtini ic gc ca Please ensure that a follow up email is sent explaining the issue being encountered Default Data There is a checkbox entitled Default Data on your worksheet This checkbox is used to determine if the Delete function will clear all user data from the worksheet or if it will restore default data in the user fields At this time this feature is not user selectable and the Delete function will reset default data in all user fields Maximize Window There is a checkbox entitled Maximize on your worksheet This checkbox will determine if the worksheet window is automatically maximized full screen on start up or if it remains in the default Window state Date The worksheet
18. isabled in this version of the worksheet E Miscellaneous None of these parameters are considered mandatory and the fields are provided simply to allow you to record the relevant information and to identify the load cell chosen It is suggested that this information be made available in case there are questions as to which load cell was used for a given installation F Notes This section is provided for you to record any further information that you feel may be pertinent to the scale or the installation There are several notes fields available for your own use The template may contain standard notes which may be overwritten at will Standard notes if implemented will re appear each time the template is loaded This feature allows you to specify permanent notes for your own use A couple of fields in the Notes areas may contain error checking formulas It will not hurt to overwrite these formulas with your own notes but the error checking will disappear These formulas will be reinstated the next time a new template is loaded The first two lines of the Notes fields have been identified with the symbol gt These two lines will be automatically carried forward to the notes section at the bottom of the Automatic Worksheet This allows the user to make annotations on the Automatic Worksheet and will be most useful when a hard copy of the worksheet has been printed Measurement Canada Page 13 01 Jan 2011 Load Cell Approvals LC Com
19. omatic or Manual worksheets by selecting the translate button within these screens Tip Select your language of choice and then resave the Template The selected language will now be the default each time you use the template Tip Set default parameters as appropriate and then resave the Template These parameter values will now be the default each time you use the template Tip Parameters which have been grayed out on the Data Entry Screen are non mandatory Printing amp QuickPrint Selecting either of the two PRINT icons will allow you to print a hard copy of the data There is an option on the Data Worksheet called QuickPrint Selecting QuickPrint will automatically send any print requests to the default printer without any further user intervention By unselecting QuickPrint you will be prompted to first select the printer you wish to use you will then be shown a Print Preview of your print job This option allows you to customize your print jobs The first PRINT icon is in the Automatic Worksheet If QuickPrint is selected then both the Data and the Automatic worksheets will be printed if you select this icon If QuickPrint is not selected you will be given the option of printing both the Automatic Worksheet and the Data Sheet or the Worksheet only The second PRINT icon is in the Manual Worksheet Selecting this icon will print only the Manual Worksheet Measurement Canada Page 2 01 Jan 2011 Load Cell Approvals LC Compatib
20. patibility Worksheet instructions Worksheets Use of the Automatic Worksheet is recommended If using the automatic worksheet each of these considerations will be addressed automatically If using the manual worksheet you must calculate each to ensure that the chosen parameters are acceptable for the device In any case the following will explain what calculations are being made to ensure compatibility 1 Accuracy Class of the Load Cell LC Indicator IND and Weighing Element WI This section will ensure that the load cell indicator and weighing element are all compatible The load cell class and the indicator class must be at least the same as or better than the configured weighing element class OIML load cell classifications are indicated by the letters A B C amp D which are roughly equivalent to NAWDS Class I II IT amp UII devices Class IHD requires a Class MW MIL or C load cell 2 Temperature Limits of the Weighing Element WI compared with the temperature limits of the Load Cell LC and the Indicator IND in C The temperature limits of the load cell and the indictor must be at least as large as the temperature limits for the weighing element In no case will a range be specified outside of 10 C and 40 C 3 Sum of the squares of the fractions pi of the maximum permissible errors for Load Cells Indicator and Weighing Element This item ensures that the error apportionment is distributed properly for the dev
21. pprovals LC Compatibility Worksheet instructions be taken from the NOA when possible The number must also be within acceptable range for the device Class chosen 3 Load cell excitation voltage Uexc Enter the actual or nominal load cell excitation voltage being provided by the indicating element This value must be within range for the chosen load cell This information should be available from the indicating element manufacturer Must be entered in volts v 4 Minimum Input Voltage Umin This is the minimum acceptable input signal voltage of the indicating element This information should be available from the indicating element manufacturer Must be entered in millivolts mV 5 Minimum Input voltage for a single scale interval AU min Enter the minimum acceptable voltage required by the indicating element to resolve a single scale interval This information should be available from the indicating element manufacturer Must be entered in microvolts uV 6 Minimum Load Cell impedance RL min For now this is a non mandatory field Enter the lowest load cell impedance that the indicating element is capable of driving Must be entered in ohms Q 7 Maximum Load Cell impedance RL max For now this is a non mandatory field Enter the highest load cell impedance that the indicating element is capable of driving Must be entered in ohms Q 8 Temperature Limits for the Indicating Element This should be a range of 10 to 4
22. reen Amber Warning in the results field indicates an undesirable situation but not necessarily one that would result in the chosen load cell being unsuitable for the application This will sometimes happen when Measurement Canada Page 4 01 Jan 2011 Load Cell Approvals LC_Compatibility Worksheet instructions data for parameters not monitored by Measurement Canada fall outside of the recommended ranges While you need not correct a Warning it is recommended that you investigate why the parameter did not Pass Manual Worksheet Screen The third screen is a copy of the Manual Worksheet and is intended to allow the user to print out copies of the worksheet to be completed manually Although data may be entered into this screen the screen is not live and no automatic calculations will take place It is up to the user to make the calculations manually It is recommended that you use the Automatic sheet whenever possible to ensure accurate calculations In all cases each shaded field must be completed as appropriate Care must be taken especially with the Manual Worksheet to ensure that the correct fields are completed when selecting Single Range Multiple Range or Multi Interval as the appropriate fields are selectively shaded depending upon the settings in the Data Entry Screen First Run Disclaimer The first time the worksheet is run the user will have to accept a disclaimer This disclaimer is to ensure the user understands that use of
23. rement Canada will make no distinction between NH No Humidity testing CH Condensating Humidity testing or SH Static Temperature Humidity testing In the absence of marking on an OIML approved cell CH may be assumed OIML Load cells must have been approved under the R60 Mutual Acceptance Arrangement These can be identified by the OIML logo with the stylized letters MAA as depicted above either on the cell or the accompanying certificate The remaining required information should be available on the Certificate that accompanies the load cell Search OIML Certificates of Conformity at http oiml org certificates Measurement Canada Page 19 01 Jan 2011 Load Cell Approvals LC_Compatibility Worksheet instructions NTEP Load Cell http www ncwm net content ntep NTEP Load Cells will generally have the required information spelled out on the cell and or in the accompanying certificate and documentation The NTEP cells will have a further marking of S for Single Cell applications and M for Multiple Cell applications NTEP allows S marked cells to be used in any application while M marked cells may only be used in multiple cell applications Measurement Canada will make no distinction between S and M marked load cells Manufacturer Fictitious Scale Company Model 123 ABC S N 1234567890 100 Certificate 100 1 Class III n 10 000 Cap 50K at 3 0491 mv V S N 1234567890 Capacity is shown as 50 000 lbs and repres
24. s now include a Date field This field is automatically set when the worksheet is first saved and cannot be changed This feature will only work as expected if the application is being used as a Template recommended Client ID Scale ID Values entered on the first line of the Client ID and Scale ID user boxes will be carried over to the Automatic Worksheet This data will appear immediately below the worksheet title This information will assist in identification of the Automatic Worksheets and will be most useful for printed copies Measurement Canada Page 3 01 Jan 2011 Load Cell Approvals LC Compatibility Worksheet instructions User Fields Both the Automatic and Manual worksheets contain a user field directly below section 10 These allow the user to make necessary notes and comments pertinent to the worksheet The user fields for the Automatic Worksheet are identified with the symbol gt These fields will be completed from the corresponding Note fields part F from the Data Worksheet Screens The template contains three user screens These are referred to as Data Automatic and Manual The names are located in the Worksheet Tabs If you see additional Tabs then you have an unprotected worksheet that may not operate as expected Please contact Measurement Canada for an updated copy Each of the three screens may be chosen by clicking on the applicable tab The screens may also be selected using the keyboard by pressing Ctrl Shif
25. t PgUp PgDn Please note that due to a quirk in some versions of Excel this will not work to navigate away from the DATA worksheet It is recommended that you simply select the appropriate tab with your mouse Data Entry Screen The first is the Data Entry Screen and is the only screen that the user needs to access to enter data All data entered in this screen will be reflected as results in the Automatic screen There is some simple data checking in this screen If you enter an invalid response in a cell you may get an error message or the data may turn red Either of these indicates a problem Please note that not all parameters are being error checked It is up to the user to ensure that valid data is entered into the appropriate field Refer to the Parameters section below for a more detailed discussion regarding how to fill out the Data fields Automatic Worksheet Screen The second screen is the Automatic Worksheet and is intended as output only The data entered into the Data screen is used to complete the outputs in this screen In this view you will be able to see at a glance whether or not the load cell parameters match up correctly with the indicating and weighing elements A PASS FAIL WARNING results field is shown in green red amber respectively If all the results fields show Green Pass then the cell is acceptable for use in the device If any of the fields are Red Fail then there is a problem that must be addressed in the Data sc
26. te Vmin may be different for OIML vs NTEP cells and the appropriate value must be entered 9 Y is a calculated value known as Relative Vmin Y is the ratio of the Maximum Cell Capacity Emax to the Minimum Load Cell Verification Interval Vmin This ratio describes the resolution of the load cell independent from the load cell capacity Y Emax Vmin Do not enter a value in this field 10 Z is a calculated value known as Relative DeadLoad Output Return DR Z is the ratio of the Maximum Load Cell Capacity Emax to twice the Minimum Deadload Output Return This ratio is used to describe multi interval devices Z may be assumed to be equal to nrc Z Emax 2 X DR or Z nc Do not enter a value in this field 11 Input Resistance Rc For now this is a non mandatory field This is a manufacturer specified parameter and may be found in the NOA for the load cell 12 Fraction of the maximum permissible error mpe for the load cells pic Unless otherwise specified in the NOA this value shall be 0 5 If changing this from the default value you are advised to discuss the implications with your Gravimetric Measurement Canada Page 12 01 Jan 2011 Load Cell Approvals LC_Compatibility Worksheet instructions Specialist The total mpe for the system must fall within a range and this value may not be changed without adjusting the fraction of the mpe values for the other components comprising the system This field has been d
27. the worksheet is accepted at the user s own risk You must accept this or the worksheet will be disabled 1 The Automated Worksheet is being provided solely for informational purposes and is not intended to provide specific advice or recommendations in any circumstances Measurement Canada does not retain any of the data entered into the Worksheet and all data remains on the user s computer Users assume the risk associated with the use of this site and with the use of their own computers The Pass Fail determination is based on the information provided by the user therefore it may only be relied upon if the information has been accurately entered La feuille de calcul automatis e est fournie a des fins informatives seulement et ne vise pas a formuler de conseils ni de recommandations Mesures Canada ne conserve aucune donn e consign e dans la feuille de calcul toutes les donn es demeurent dans le syst me de l utilisateur Les utilisateurs acceptent les risques li s a l utilisation du pr sent site et de leur propre syst me La d termination de l acceptation ou du rejet est fond e sur les renseignements fournis par l utilisateur Par cons quent ils ne sont fiables que lorsque l information consign e est exacte 2 Her Majesty assumes no responsibility for any errors omissions or misleading statements obtained through the use of the Automated Worksheet The data information or results obtained through the use of the Worksheet have
28. ufacturer s rating for maximum safe overload This is the maximum load that may be applied to a load cell without causing a permanent degradation of the performance of that cell This parameter is often expressed as a percentage of Emax and if so it must be converted to and entered in the same units as LRE Max above Measurement Canada Page 11 01 Jan 2011 Load Cell Approvals LC Compatibility Worksheet instructions 5 Temperature Limits for the Load Cell This should be a range of 10 to 40 degrees Celsius unless otherwise stated in the NOA for the cell These values must be entered in degrees Celsius C 6 Rated Cell output in mV V C Manufacturer s rated load cell output in millivolt output signal per volt input excitation In the case of a multi cell scale where the manufacturer supplies actual cell output for each cell please enter the nominal cell output in this field e g actual cell output 3 002 3 000 3 002 3 001 enter 3 0 mV V 7 Number of Load Cell Intervals nic Approved number of intervals for the load cell This number will be available on the load cell certificate and must be appropriate for the Class of device being installed OIML cells will often show this value in terms of 1000 intervals e g a C3 load cell would be a Class C approved to 3000 intervals 8 Minimum Load Cell verification interval Vmin Smallest approved load cell interval This parameter will be listed on the cell certifica
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