供應(yīng)雙絲像質(zhì)計(jì)（雙線型像質(zhì)計(jì)/ 雙線型IQI）
雙絲像質(zhì)計(jì)（雙線型像質(zhì)計(jì)，雙線型IQI）根據(jù)ISO19232-5/EN462-5/ASTM  E2002標(biāo)準(zhǔn)生產(chǎn)，ISO19232-5/  EN462-5/ASTM  E2002  雙絲像質(zhì)計(jì)（雙線型像質(zhì)計(jì)，雙線型IQI）是由放置于剛性半透明塑料盒中的13個(gè)線對組成，雙絲像質(zhì)計(jì)絲的直徑與絲與絲之間的距離相等，每個(gè)線對包含兩條圓形截面的線。1D至3D線對是金屬鎢，其它線對是金屬鉑。雙絲像質(zhì)計(jì)（雙線型像質(zhì)計(jì)，雙線型IQI）用于確定射線照相和實(shí)時(shí)射線透照系統(tǒng)的幾何不清晰度。

  



  

                  雙絲像質(zhì)計(jì)（雙線型像質(zhì)計(jì)，雙線型IQI）應(yīng)與線型或孔型像質(zhì)計(jì)一起使用。雙絲像質(zhì)計(jì)應(yīng)置于被檢物體的源側(cè)，并且應(yīng)盡可能地靠近射線束軸線與軸線垂直。應(yīng)借助4倍放大鏡觀察雙絲像質(zhì)計(jì)影像。最大線對，其影像正好是兩雙線間距可以識(shí)別極限下的兩獨(dú)立線過渡到單線的影像，此時(shí)被認(rèn)為是可辨別的極限值。圖像不清晰度U可由2d表示，其中d是線的寬度和線的間隔距離（見下表）。



絲的代號(hào)          幾何不清晰度U(mm)          絲的直徑d(mm)
      13D                          0.10                                      0.050
      12D                          0.13                                      0.063
      11D                          0.16                                      0.080
      10D                          0.20                                      0.100
        9D                          0.26                                      0.130
        8D                          0.32                                      0.160
        7D                          0.40                                      0.200
        6D                          0.50                                      0.250
        5D                          0.64                                      0.320
        4D                          0.80                                      0.400
        3D                          1.00                                      0.500
        2D                          1.26                                      0.630
        1D                          1.60                                      0.800


                  對每個(gè)雙絲像質(zhì)計(jì)，制造商都應(yīng)提供合格證明書。

                  注：雙絲像質(zhì)計(jì)（雙線型像質(zhì)計(jì)，雙線型IQI）不能代替線型或階梯/孔型像質(zhì)計(jì)，因?yàn)樗鼉H僅反映不清晰度。