Maximum Error In Voltage
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found by measurement and the "true value' of the quantity. eg an object that has a mass of 120 g may be shown to weigh 130 g on an imperfect weighing machine. True weight: 120 g Measured voltmeter error weight: 130 g Error: +10 g Measurement errors arise because of how to calculate absolute error inevitable imperfections in the measuring instrument and limitations of the human eye. Errors come in all sizes, and sometimes you absolute error formula need to decide if the error in your measurement is so big that it makes the measurement useless. (see examples below) Errors can be positive or negative. An electric current might relative error formula be measured as Examples The effective size of the error depends on the actual size of the error the size of the measurement itself Example 1 Measuring a Line Actual length of line: 11 cm Length of line when measured: 12 cm Error is (Measured Length - Actual Length) Error is (12 cm - 11 cm) = 1 cm. The error
Percentage Error
expressed as a fraction of the actual size is Example 2 Measuring the height of a person Actual height is 1.72 cm = 1270 mm If the error in measurement is only 1 mm, then expressing this as a fraction of the actual size Have a Go Problem 1 Voltage is measured with a multimeter. A particular multimeter is being tested. True voltage of the multimeter: 224 V. Measured voltage: 220 V. Calculate the actual error and the percentage error. You will notice that in this example the error is a negative value Problem 2 Another multimeter is being tested. True voltage of the multimeter: 150 V Measured voltage: 153 V Calculate the actual error and the percentage error. In this case the error has a positive value. Practice Questions Question 1 Answer 1.3 hectares Question 2 answer + or - 0.2% Question 3 answer + or - 0.2 cm Question 4 answer + or - 32.2 sec Question 5 answer + or - 0.2% Question 6 answer + or - 1.2% Solution 1 Actual Error = Measure
Bio Email This Print Comment 7 comments Login50%50% Introduction When using a current sense amplifier, it is important to know how much error is present in the
Error Propagation
output so an accurate interpretation of the data can be obtained. Output error can uncertainty calculator be measured by the Output High Voltage parameter of the amplifier which is defined as the difference in voltage between a percent error calculator VRS- pin and an Output pin. The typical error that can be expected for any current sense amp will be defined in the Electrical Characteristics (EC) table found on its datasheet. Although this rate is http://www.staff.vu.edu.au/mcaonline/units/percent/pererr.html what one can expect for most cases, it is still important to know how this parameter is calculated based upon the amplifier's circuit design. To do this, we will demonstrate how to do an error budget analysis calculation. Calculation demonstration For the purposes of this demonstration, we are using the Touchstone TS1100 current-sense amplifier although the process can be applied to any current sense amplifier. In this case, the amplifier has http://www.planetanalog.com/author.asp?section_id=3026 a voltage power supply of 3.6V and a gain of 100V/V. First, the full scale voltage across the RSENSE resistor must be found. The equation for the full scale VSENSE is: VSENSE(FS) = VSUPPLY/GAIN [1] Substituting the 3.6V power supply and the 100V/V gain option into equation [1], the resulting full scale VSENSE is shown below. VSENSE(FS) = 0.036 V Next, the gain across the amplifier's entire temperature range (-40°C to +105°C) must be found. The maximum gain error across the entire temperature range must be calculated. The maximum Gain Error (GE) across temperature can also found in the EC table on the datasheet, and shown below. GE = ±0.6% Considering the plus-minus error specification, a maximum and minimum swing for the gain across temperature is found. The inequality is defined below. GAIN⋅(1-GE) ≤ GAIN ≤ GAIN⋅(1+GE) [2] Solving the inequality results in the amplifier exhibiting the following gain over the entire temperature range. 99.4V/V ≤ GAIN ≤ 101.6V/V Now, the voltage output can be determined by calculating the effects from the input offset voltage over temperature. The voltage output equation to solve for is: VOUT = [GAIN⋅(1±GE)⋅VSENSE(FS)] ± [GAIN(1±GE)⋅VOS] [3] The Input Offset Voltage parameter is also listed in the EC table. For this demonstration, the maximum and minimum in
whole-cell patch clamp experiment? I compensate my series resistance 75-80%, I have sodium currents that range from 0.5 to 6 nA, and my pipettes are 1.5-3 megaohms. Topics High Voltage https://www.researchgate.net/post/How_can_I_calculate_the_voltage_error_in_a_whole-cell_patch_clamp_experiment Engineering × 94 Questions 541 Followers Follow Voltage Clamp × 35 Questions 92 http://www.skillbank.co.uk/SignalConversion/snr.htm Followers Follow Electrophysiology × 471 Questions 7,623 Followers Follow May 14, 2014 Share Facebook Twitter LinkedIn Google+ 2 / 0 All Answers (3) Rheanna M. Sand · Boston Children's Hospital Thanks Paul! Your explanation is very helpful. So, given the following, are my calculations correct? - the dial for series resistance on the absolute error amp reads 0.3 (= 3 megaohms) - the compensation dial reads 75% - the maximal current at one point in time is 6 nA - the command voltage is to -10 mV Ru = 3 * 25 / 100 = 0.75 megaohms Vm = (-10 mV) - (6 nA * 0.75 megaohms) (after converting everything into volts, amps, and ohms) Vm = -14.5 mV And to your maximum error in point of clarification - I can say then that the maximum voltage error for this experiment is 4.5 mV (since the 6 nA is the maximal current), but not that the voltage error for the entire sweep is 4.5 mV. Jul 31, 2014 Can you help by adding an answer? Add your answer Question followers (6) Xiping Zhan Howard University Arthur Beyder Mayo Clinic - Rochester Michel J Roux Institut de Génétique et de Biologie Moléculaire et Cellulaire Rheanna M. Sand Boston Children's Hospital Cheng-Chang Chen Ludwig-Maximilians-University of Munich Views 671 Followers 6 Answers 3 © 2008-2016 researchgate.net. All rights reserved.About us · Contact us · Careers · Developers · News · Help Center · Privacy · Terms · Copyright | Advertising · Recruiting We use cookies to give you the best possible experience on ResearchGate. Read our cookies policy to learn more.OkorDiscover by subject areaRecruit researchersJoin for freeLog in EmailPasswordForgot password?Keep me logged inor log in with ResearchGate is the professional network for scientists and researchers. Got a question you need answered quickly? Technical questions like the one you've just found usually get answered within 48 hours on ResearchGate. Sign up today to join our community of over 11+ million scientific professionals. Join for free An error occurred while rendering template. rgreq-2700a063dded33c283bb5f277847eae4 false
Data Conversion Website Quantization Error and Signal - to - Noise Ratio calculations The signal to noise ratio of a quantized signal is 2+6*(no of bits), as shown in the following table. Resolution and Signal to Noise Ratio for signals coded as n bits bits, n levels, 2n Weighting of LSB, 2-n SNR, dB 1 2 0.5 8 2 4 0.25 14 3 8 0.125 20 4 16 0.0625 26 5 32 0.03125 32 6 64 0.01563 38 7 128 0.00781 44 8 256 0.00391 50 9 512 0.00195 56 10 1024 0.00098 62 11 2048 0.00048 68 12 4096 0.00024 74 13 8192 0.00012 80 14 16384 0.00006 86 15 32768 0.00003 92 16 65536 0.00001 98 These values are for a signal matched to the full-scale range of the converter. If a signal with a range of 5V is measured by an 8 bit ADC with a range of 10V then only 7 bits are effectively in use, and a signal to noise ratio of 44 rather than 50 will apply. Proof: Suppose that the instantaneous value of the input voltage is measured by an ADC with a Full Scale Range of Vfs volts, and a resolution of n bits. The real value can change through a range of q = Vfs / 2n volts without a change in measured value occurring. The value of the measured signal is Vm = Vs - e, where Vm is the measured value, Vs is the actual value, and e is the error. The maximum value of error in the measured signal is emax = (1/2)(Vfs / 2n) or emax = q/2 since q = Vfs / 2n The RMS value of quantization error voltage is whence The Signal to Noise Ratio (SNR) is defined as It is normally quoted on a logarithmic scale, in deciBels ( dB ). or The RMS signal voltage is then The error, or quantization noise signal is Thus the signal - to - noise ratio in dB. is since Vfs = 2n q, then which simplifies to N.B. This equation is true only if the input signal is exactly matched to the Full Scale Range of the converter. For signals whose amplitude is less than the FSR the Signal - to - Noise Ratio will be reduced. Download a .pdf file of the analysis of quantization error and signal to noise ratio