[电] watt-hour constant of a meter

yí biǎo de wǎ tè xiǎo shí cháng shù ㄧˊ ㄅㄧㄠˇ ㄉㄜ˙ ㄨㄚˇ ㄊㄜˋ ㄒㄧㄠˇ ㄕˊ ㄔㄤˊ ㄕㄨˋ