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Showing posts from July, 2021

KVAR RATING CALCULATOR,CAPACITOR BANK SIZE CALCULATION

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  Determination of Required Capacitor Rating by measurement 3 Methods are used. 1. Measurement with current and power factor 2.Measurement with recording of Active and Reactive power. 3.Measurement by Reading Meters . 1 . Measurement with Current and power factor The active power P is calculate from the measured voltage V ,apparent current Is and Power Factor P=√3*Voltage*apparent Current*cosψ *10^-3 If the desired power factor cosψ has been specified, the capacitor power rating can be calculate from the following formula: Qc = P. (tan ψactual - tanψ desired) Let's See the Example Measured Apparent Current Is : 248 Amps Power Factor cos ψ1 = 0.86 Desired Cos ψ2 = 0.92 Voltage V :397 V p=√3 * 397 * 248 * 0.86 * 103 P = 146.6 KW Qc= P. (tanψ actual - tanψ desired) = 146.6(0.59 - 0.42) = 24.9 KVAR

ACCURACY OF GRADE ZERO GAUGE BLOCKS BASED ON BS 4311:PART 1:1993

 Grade 0 gauge blocks are very high accuracy It is used in controlled environment by skilled inspection staff It is the reference standard used to calibrate / verification of other lower grade . Here the accuracy and tolerance of the Gauge block set are bellowed mentioned please go throng the standard based on BS 4311:Part 1 Nominal Length (inch) Tolerance of deviation of measured central length (inch) Parallelism (inch) Flatness (inch) Over 0 Up to 0.4 ± 5 µin 4 µin 4 µin Over 0.4 Up to 1 ± 6 µin 4 µin 4 µin Over 1 Up to 2 ± 8 µin 4 µin 4 µin Over 2 Up to 3 ± 10 µin 5 µin 4 µin Over 3 Up to 4 ±12 µin 5 µin 4 µin Usage        ...

EXPANDED FORM OF BRINELL HARDNESS SCALE - HOW TO READ THE BRINELL HARDNESS SCALE

BRINELL HARDESS SCALE REPRASENTATION WW HBW XX/YY/ZZ 350 HBW 5/750/10   WW : Brinell Hardness Numbers shall be followed by the symbol HBW , XX:.Diameter of the ball ,mm YY :Test force ,kgf ZZ:Applied Force dwell time,s   READING METHOD OF BRINELL HARDNESS SCALE  Brinell Hardness Scale Expanded From of Hardness Scale 350 HBW 5/750 Brinell Hardness of 350 determined with a ball of 5mm diameter and with a test force of  750 kgf applied for 10s to 15 s 600 HBW 1/30/20 Brinell Hardness of 600 determined with a ball of 1 mm and with a test force of 30 kgf of  20s   Brinell Hardness Number is calculated Brinell Hardness Number A number, which is proportional to the quotient obtained by dividing the test force by the curved surface of the indentation which is assumed to be spherical and of the diameter of the ball How to find the Hardness Number (HBW) Brinell Hardnes...

CMC VALUE CALCULATION FROM THE SCOPE OF ACCREDITATION

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  DC CURRENT CMC CALCULATION CMC=Calibration measurement capability Calibration and Measurement Capability (CMC) is the smallest uncertainty of measurement that a laboratory can achieve within its scope of accreditation when performing more or less routine calibrations of nearly ideal measurement standards or nearly ideal measuring equipment. Calibration and Measurement Capabilities represent expanded uncertainties expressed at approximately the 95 % level of confidence, usually using a coverage factor of k = 2. The actual measurement uncertainty of a specific calibration performed by the laboratory may be greater than the CMC due to the behavior of the customer’s device and to influences from the circumstances of the specific calibration. Figure below the how the Accredited Scope given the CMC of the DC Current CMC From the Scope of Accreditation Unit Under Test(UUT) instrument  Expanded uncertainty should always is  greater than the CMC 0 µA to 329.999 µA   -----...

Melting point of elements and alloys

  Element or alloy Symbol Melting point (°C) Carbon C 3600 Tungsten W 3000 Titanium Ti 1795 Platinum Pt 1772 Chromium Cr 1615 Iron Fe 1530 Cobalt Co 1495 Carbon Steel,low Cr + Ni +Mn +C 1464 Nickel Ni 1452                                                                                                                   

LS-1008 LEAD SETTING STANDARD NOMINAL VALUE AND ACCURACY OR TOLERANCE AS PER API

All the values are inch   GROOVE DISTANCE #1 - #2 Nominal Value        0.503900 REMAINING GROOVES Nominal Value  +1.007800 +2.015600 +3.023300 +4.031100 ACCURACY OR TOLERANCE The Accuracy or tolerance of the groove distance between 1 and 2 are given below. Groove distance #1 - #2     +0.000100"/-0.000100 The Accuracy or tolerance of the remaining groove are given below +0.000200/-0.000200

ACCURAY OF BRINELL HARDNESS INDENTATION MEASURING DEVICE AS PER ASTM STANDARD

  BRINEL HARDNESS BALL DIAMETER MEASUREMENT DEVICE & ACCURACY OR PERMISSIBLE ERROR OR ACCEPTANCE CRITERIA   Ball diameter measurement device is the integral part or standalone part of the Hardness machine. The measurement devices are classified into two types. Type A Device & Type B device Type A Type B Includes microscope having movable measuring line. Use some type of indicator or computerised measuring system or image analysis system. Hand held microscope with fixed measuring lines   Usually used (20X or 40X)     Resolution and Graduation Spacing of Indentation Measuring Device Ball Diameter (mm) Type A Type B Minimum indicator Resolution (mm) Maximum Graduation Spacing (mm) 10 0.0100 0.100 5 0.0050 0.050 2.5 0.0025 - ...

BRINELL HARDNESS ASTM E10 SYMBOL AND DESIGNATIONS

  Symbol Designation Unit D Diameter of the ball mm F Test Force N F kgf Test Force kgf d Mean Diameter of the indentation mm h Depth of the indentation mm Force Diameter Ratio \[\frac{Fkgf}{D^2}\] - HBW Brinell Hardness Test Force / Surface area of Indentation \[\frac{Fk...