Definition on bekc

8/9/2019 Definition on bekc

1/5

1. General: Device that communicates, denotes, detects, indicates, measures,

observes, records, or signals a quantity or phenomenon, or controls or

manipulates another device.

2. Law: Formally executeddocument that evidences a legally enforceable

agreement between two or more parties, and expresses a contractual duty,

obligation, or right. Practically all documents used in borrowing, lending,

investing, and sale and purchase on credit, are legal instruments.

Definition: Measurement is collection of quantitative data. A measurement is made by comparing

a quantity with a standard unit. Since this comparison cannot be perfect, measurements inherently

include error.

accuracy: The degree of conformity of a measured or calculated value to its actual or specified value

precision: 1. The degree of mutual agreement among a series of individual measurements, values,

or results; often, but not necessarily, expressed by the standard deviation. 2. With respect to aset of

independent devices of the same design, the ability of these devices to produce the same value or

result, given the sameinput conditions and operating in the same environment. 3. With respect to a

single device, put into operationrepeatedly without adjustments, the ability to produce the same

value or result, given the same input conditions and operating in the same environment. Synonym (for

defs. 1, 2, and 3)reproducibility. 4. In computer science, a measure of the ability to distinguish

between nearly equal values. (188) 5. The degree of discrimination with which a quantity is stated; for

example, a three-digit numeral to the base 10 discriminates among 1000 possibilities.

Expected value

1. The sum of all possible values for a random variable, each value multiplied by its

probability of occurrence.

2. The integral of the probability density function and a continuous random variable over

its range of values.

error

3. 1. An act, assertion, or belief that unintentionally deviates from what is correct, right, or true.

4. 2. The condition of having incorrect or false knowledge.

5. 3. The act or an instance of deviating from an accepted code of behavior.

6. 4. A mistake.

7. 5. Mathematics The difference between a computed or measured value and a true or

theoretically correct value.

8. 6.Abbr. EBaseballA defensive fielding or throwing misplay by a player when a play normally

should have resulted in an out or prevented an advance by a base runner.

9.
http://www.businessdictionary.com/definition/device.htmlhttp://www.businessdictionary.com/definition/measures.htmlhttp://www.businessdictionary.com/definition/record.htmlhttp://www.businessdictionary.com/definition/signal.htmlhttp://www.businessdictionary.com/definition/quantity.htmlhttp://www.businessdictionary.com/definition/control.htmlhttp://www.businessdictionary.com/definition/law.htmlhttp://www.businessdictionary.com/definition/executed.htmlhttp://www.businessdictionary.com/definition/document.htmlhttp://www.businessdictionary.com/definition/evidence.htmlhttp://www.businessdictionary.com/definition/agreement.htmlhttp://www.businessdictionary.com/definition/party.htmlhttp://www.businessdictionary.com/definition/duty.htmlhttp://www.businessdictionary.com/definition/obligation.htmlhttp://www.businessdictionary.com/definition/documents.htmlhttp://www.businessdictionary.com/definition/borrowing.htmlhttp://www.investorwords.com/5909/lending.htmlhttp://www.investorwords.com/5906/investing.htmlhttp://www.businessdictionary.com/definition/sale.htmlhttp://www.businessdictionary.com/definition/purchase.htmlhttp://www.businessdictionary.com/definition/credit.htmlhttp://www.businessdictionary.com/definition/legal-instrument.htmlhttp://www.its.bldrdoc.gov/fs-1037/dir-033/_4806.htmhttp://www.its.bldrdoc.gov/fs-1037/dir-033/_4806.htmhttp://www.its.bldrdoc.gov/fs-1037/dir-019/_2740.htmhttp://www.its.bldrdoc.gov/fs-1037/dir-019/_2740.htmhttp://www.its.bldrdoc.gov/fs-1037/dir-025/_3691.htmhttp://www.its.bldrdoc.gov/fs-1037/dir-025/_3691.htmhttp://www.its.bldrdoc.gov/fs-1037/dir-008/_1196.htmhttp://www.its.bldrdoc.gov/fs-1037/dir-001/_0063.htm#188http://www.its.bldrdoc.gov/fs-1037/dir-001/_0063.htm#188http://www.its.bldrdoc.gov/fs-1037/dir-011/_1632.htmhttp://www.businessdictionary.com/definition/measures.htmlhttp://www.businessdictionary.com/definition/record.htmlhttp://www.businessdictionary.com/definition/signal.htmlhttp://www.businessdictionary.com/definition/quantity.htmlhttp://www.businessdictionary.com/definition/control.htmlhttp://www.businessdictionary.com/definition/law.htmlhttp://www.businessdictionary.com/definition/executed.htmlhttp://www.businessdictionary.com/definition/document.htmlhttp://www.businessdictionary.com/definition/evidence.htmlhttp://www.businessdictionary.com/definition/agreement.htmlhttp://www.businessdictionary.com/definition/party.htmlhttp://www.businessdictionary.com/definition/duty.htmlhttp://www.businessdictionary.com/definition/obligation.htmlhttp://www.businessdictionary.com/definition/documents.htmlhttp://www.businessdictionary.com/definition/borrowing.htmlhttp://www.investorwords.com/5909/lending.htmlhttp://www.investorwords.com/5906/investing.htmlhttp://www.businessdictionary.com/definition/sale.htmlhttp://www.businessdictionary.com/definition/purchase.htmlhttp://www.businessdictionary.com/definition/credit.htmlhttp://www.businessdictionary.com/definition/legal-instrument.htmlhttp://www.its.bldrdoc.gov/fs-1037/dir-033/_4806.htmhttp://www.its.bldrdoc.gov/fs-1037/dir-019/_2740.htmhttp://www.its.bldrdoc.gov/fs-1037/dir-025/_3691.htmhttp://www.its.bldrdoc.gov/fs-1037/dir-008/_1196.htmhttp://www.its.bldrdoc.gov/fs-1037/dir-001/_0063.htm#188http://www.its.bldrdoc.gov/fs-1037/dir-011/_1632.htmhttp://www.businessdictionary.com/definition/device.html


2/5

10.Resolution -- the smallest amount of input signal change that the instrument can

detect reliably. This term is determined by the instrument noise (either circuit or

quantization noise). For example, if you have a noiseless voltmeter that has 5 1/2

digits displayed and is set to the 20 V input range, the resolution of this voltmeter is

100 V. This can be determined by looking at the change associated with the least

significant digit.

Now, if this same voltmeter had 10 counts of peak-to-peak noise, the effective resolution

would be decreased because of the presence of the noise. Because of the Gaussian

distribution of the noise, in this case the effective resolution would be 0.52 1 mV. In general

when you have a measurement system that has X counts of Gaussian noise, the effective

resolution of the system is given by

Error Calculation or Accuracy Determination

DC Measurement

Error Type

Reading-Dependent

Errors

Noise and Range-

Dependent Errors

Specified Accuracy % of reading x

reading/100

offset

Nonlinearity % nonlinearity x

range/100System Noise rms noise x 6.6 (to

find peak-to-peak

value)

Settling Time % settled x Step

change/100 (this must

be added for scanning

systems unless it is

included in the

accuracy

specifications)NM Noise Normal Mode Noise x

10^(-NMRR/20)

CMV Common mode

Voltage x 10^(-CMRR/20)

Temperature Drift

(this must be added if

your temperature

range is outside the

specified range for the

given accuracy tables)

(% of reading/C) xX

C x reading/100

Xis the temperature

difference between

the specified

temperature range andthe actual operating

(offset /C) xXC

Xis the temperature

difference between the

specified temperature

range and the actual

operating temperature.


3/5

temperature.

Let us consider the National Instruments NI 4350 Series 5 1/2 digit Temperature and Voltage

Data Logger. We will calculate the total accuracy of a 1 V reading. Let us also assume that

the instrument is at an ambient temperature between 15 and 35 C, and it has been less than a

year since the last calibration was performed but more than 90 days. The total accuracy based

on the error budget determined above is:

Error Type

Percent of Reading

Errors

Range-Dependent

Errors

Specified Accuracy 1 V x 0.0131% = 131

mV

3 V

Nonlinearity 0, included in accuracy

System Noise 0, included in offset

Settling Time not needed asspecification table

included any errors

due to scanning

NM Noise, assume 1

mVrms of

environmental noise

1 mV x 1.4 x l0^(-100/20)

= 0.01 V

CMV, assume

maximum CMV of

2.5 V

2.5 x 10^(-100/20) = 25 V

Temperature Drift N/A (because the NI4350 specification

tables cover 15 to 35

C)

N/A (because the NI4350 specification

tables cover 15 to 35

C)

Subtotal 131 V 28.01 V

Total Maximum Error 159.01 V or 0.016% of reading

AC Measurement

Error Type

Reading-Dependent

Errors

Range-Dependent

Errors

Specified Accuracy at

a Given Signal

Frequency Range

% of reading x

reading/100

offset

Nonlinearity % nonlinearity x

range/100

System Noise rms noise x 3.46 (to

find peak to peak

value x assumegaussian noise)


4/5

Settling Time % settled x Step

change/100 (this must

be added for scanning

systems unless it is

included in the

accuracyspecifications)

CMV Common mode

voltage x 10^(-CMRR/20)

Temperature Drift

(this must be added if

your temperature

range is outside the

specified range for the

given accuracy tables)

(% of reading/C) xX

C x reading/100

Xis the amount of

temperature drift from

the specified

temperature range.

offset /C xXC

Xis the amount of

temperature drift from

the specified

temperature range.

Crest Factor Error Xx reading/100

AddX% additional

error based on the

type of waveform.

Let us consider the NI 4050 5 1/2 digit multimeter and calculate the total accuracy of a 1

Vrms reading. Let us also assume that the instrument is at an ambient temperature between

15 and 35 C, and it has been one year since the last calibration was performed. Because this

is an AC measurement, we need to specify the frequency of the signal measured and the crest

factor. Let us assume a frequency of 1 kHz and a crest factor of 2. The total accuracy based

on the error budget determined above is:

Error Type

Reading-Dependent

Errors

Range-Dependent

Errors

Specified Accuracy at

a Given Signal

Frequency Range

0.42% x 1 V = 4.2

mV

1.2 mV

Nonlinearity Included in

specification table

Included in

specification table

System Noise Included in

specification table

Settling Time This is not a scanning

DMM and let us

assume that the signal

is not changing

CMV assume

maximum allowable

CMV of 250 V

250 10^(-100/20) = 2.5

mV

Temperature Drift Not applicable

because the

temperature range is


5/5

included in the

specification table

Crest Factor Error 0% x 1 V/100 = 0 mV

Subtotal 4.2 mV 3.7 mV

Total Maximum Error 7.9 mV or 0.79% of reading

Documents

Definition on bekc