KVAR RATING CALCULATOR,CAPACITOR BANK SIZE CALCULATION

-
Image
  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
Post a Comment

ACCURACY OR MAXIMUM PERMISSIBLE ERROR OF STEEL SCALE AS PER BS :4372

-

 Graduation lines shall be accurate to within the tolerances specified in table below. These tolerances apply to the distances between the centre  lines of the graduation lines.

Rule Length

Departure from nominal

Up to and inc. 300 mm

Over  300 mm up to and inc. 500 mm

Over  500 mm up to and inc. 1 m

Distance between any two graduation lines on a single scale

0.1 mm

0.2 mm

0.25 mm

Distance between any two adjacent graduation lines.

0.05 mm

0.05 mm

0.05 mm

Position of the 10 mm graduation line from its flat end datum

0.08 mm

0.08 mm

0.08 mm


















                        Accuracy of Graduation

Comments

Post a Comment

Popular posts from this blog

TOLERANCE OR MAXIMUM PERMISSIBLE ERROR OR ACCURACY OF VERNIER OF DIGITAL CALIPER AS PER BS EN ISO 13385-1:2019

-
 Calliper  Measuring instrument which evaluates a dimensional quantity of an internal or external feature of the basis of opposing contact from the movement of a slider with a measuring jaw, moving relative to a measuring scale on rigid beam and to a fixed jaw. Maximum permissible error (MPE) values apply to any indication permitted for use of calliper as defined by the manufacturer and when used in accordance with the manufacturer's recommendation .The MPE Values cannot be smaller than the digital step or the scale interval on the circular scale or vernier scale There are mainly three Error are consider in the calliper .Partial Surface contact error , E ( limited by   E MPE ) Shift Error ,S (limited by  S MPE ) Line Contact Error DEFAULT MPE (Maximum Permissible Error ) for metrological characteristics If no MPE values are otherwise stated then the values in tables apply for callipers with a measuring range up to 1000 mm and with analogue scale interval or digital step of 0.01 mm
Read more

HOW TO CALCULATE THE UNCERTAINTY BUDGET OF pH METER.

-
Image
1. SOURCES OF UNCERTAINTY A. Repeatability (Type A) B. Buffers (Type B) C. Resolution of pH meter (Type B) D. Linearity (Type B) E. Temperature (Type B) 2. Quntification of Sources of Uncertainty A. Repeatability (Type A)                 Repeatability calculation (Type A Uncertainty)                             Formula / Expression of find the Repeatability (Standard uncertainty) Mean = AVERAGE(B4:B13) (X - Mean) = $B4-$C$4                   =UUT Value - Mean (X - Mean)^2 = ($D4)^2                             =( UUT Value - Mean)^2     Standard Deviation = STDEV(B4:B13)    Repeatability (Standard Uncertainty) =  F4/SQRT(10)                                                                                    =Standard Deviation / square root (number of Sample) B. Buffers: Following Buffers are used in Calibration of pH Meter: a) 4.01 with ± 0.02 uncertainty declared by manufacturer. b)7.00 with ± 0.01 uncertainty declared by manufacturer. c) 10.01 with ± 0.03 uncertainty declared by manu
Read more

Estimation of Uncertainty in Hardness Measurement & Maximum Permissible Error of Brinell Hardness Testing Machine As Per ISO 6506-2 & ASTM E10-15

-
Image
Source of Uncertainty of Hardness Measurement Certified Value of CRM Determine the User Machine Repeatability Assessment according EN ISO 6506 Uncertainty from the Measured Material. Resolution of the Indentation diameter measuring device.                            1. Certified Value of CRM       Xcrm = 222 HBW 10/3000    Ucrm    = 土 1.4 HBW  (2σ Uncertainty) 2 . Determine the User Machine Repeatability       H₁ = 221     H₂ = 220      H₃ = 220      H₄ = 221      H₅ = 220     Mean = 220  HBW                      b )  Repeatability of  Hardness Measurement                      H₅ = 220                          H₁ = 221                               = -1 HBW                    (C) Standard Deviation                                                                           =0.55 HBW   3. Assessment according EN ISO 6506           a)  The error ( E) of the testing machine                                                                           = 222 - 220                                 
Read more