沧州市金泰衡器有限公司-智能电子汽车衡,电子台秤,电子吊称

Electronic balance PL-204 is a common laboratory analytical instruments, we are often dealing with electronic balance , especially in high-precision, resolution, small electronic scales, such as the balance millionth 0.1mg , 0.01mg hundred thousandth day equality. In the purchase or use of these electronic days usually , we often encounter the balance repeatability error , linearity error , four errors and other parameters , which in the end is what this means , electronic scales have any effect on it, we have to share with you.

 

( 1 ) Repeatability standard deviation is expressed or whether the electronic balance accurate indicator of the standard of the electronic balance indicator is not a measure to come, but rather the result of a continuous measurement of the n-th statistical methods used to calculate the standard deviation , ie repeatability specifications .

 

e = (Xi-X) 2 / (n-1)

 

e- repetitive or standard deviation

 

X- the arithmetic mean of each measurement

 

Xi- time measurements

 

n- number of measurements ( international n = 6, China n = 11)

 

( 2 ) electronic balance corners of error

 

Objects on the weighing pan on different locations , the measurement results should be roughly the same, and to allow a certain deviation , the value is the maximum corner error . Corner error detection method is as follows :

 

According to OIML International Recommendations are based on the full-scale electronic balance 1/3 of the weight and the weighing pan radius 1 /3 of the position on the scale to measure the emergence of some corners of the error is due to the structure and assembly of the sensor caused by the deviation generated , while the maximum error is due to the length of the upper and lower linkage lever inconsistencies arising .

 

( 3 ) electronic balance linearity error

 

Electronic balance itself is not put a lot of changes linearly with the display , but a deviation , the linearity error . This error can not be completely avoided , can only choose a small coefficient of linear error component to the error as small as possible . Electronic balance linearity error is the largest source of permanent magnet within the sensor magnetic field lines generated by the non-linearity caused , which can not be avoided . In order to maintain the accuracy of electronic balance , Ho Chi Chengdu Instrument Co. Supply has designed a unique automatic tracking compensation circuit high accuracy balance.

 

Since amplification components and magnetic cylinder linearity error is generated by the analog to digital converter in front , so we designed a linear compensation circuit attached to the ADC error correction of plus points admiral . We can adjust the variable resistor P1, adjust the required compensation voltage amplitude linearity error of depth to match the input to the ADC before leaving no deviation is a simulation of the signal it.