The sample temperature was controlled by a chromel _ alumel thermocouple with a precision on the order of 0 . 1 此次田间试验的目的，是研究这一方法能在多大程度上防止由于精细的作物轮作所产生的土壤退化。
2.
4 . the thrust measurement device was calibrated , and the accuracy was 2 % fs . at the same time the signal of thrust measurement was input to the computer . e - type chromel - constantan thermocouple was used to measure the temperature of mpt , and the accuracy was 5 % fs . the vacuum measurement was realized by using zdf - 5427m vacuometer , and the accuracy was 3 % fs ( 4 )对推力测量系统进行了标定并实现了计算机采集，推力测量系统最大相对误差为2 fs ；温度测量目前还只限于对mpt谐振腔壁温的测量，使用e型镍铬?康铜热电偶即可较容易实现，其测量精度为5 fs ；真空测量采用zdf - 5427m微机型复合真空计，其由热偶计和热阴极电离计复合而成，该真空计测量控制精度为3 fs 。
