rider

…The distance between the fulcrum and the point of force, and between the fulcrum and the point of gravity (the length of the arm) are not exactly equal, so to measure with an accuracy better than 1× ^10-4 , the double weighing method, in which the left and right positions are swapped and the average of two measurements is taken, and the substitution weighing method, in which the object and the weight are replaced on the same pan and the same arm is used, are used to eliminate errors due to deviations in the arm length (deviations in the ratio). Adding or removing minute masses is done by moving a linear auxiliary weight called a rider on the rider beam, and the slight difference between the zero point and the rest point is converted into a mass difference by multiplying it by the reciprocal of the sensitivity. The capacity of manual balances is about 0.1g to 1000kg, and the sensitivity is ^1/104 to ^1/106 of the capacity, and they are classified as follows according to their precision and purpose of use: …

*Some of the terminology that mentions "rider" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…支点と力点，支点と重点の距離(腕の長さ)は厳密には等しくないので，1×10^－4よりよい精度の測定には，左右の配置を入れかえた2回の測定の平均値をとる二重秤量法，同じ皿上で物体と分銅とを置換し，同じ腕を共用する置換秤量法を用い腕の長さの狂い(比の狂い)による誤差を消去する。微小な質量の加減はライダーriderと称する線状の補助分銅をライダーざお上で移動して行い，わずかな零点と静止点との差は感度の逆数を乗じ質量差に変換する。　手動てんびんの秤量は0.1g～1000kg程度，感量は秤量の1/10⁴～1/10⁶で，精密さ，使用目的に応じて次のように分類される。…

※「rider」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報