測試設(shè)備廠商通過“線性”來描寫光功率計(jì)的準(zhǔn)確度，線性是光功率計(jì)知道的參數(shù)，福祿克SImpliFiber PRO光功率計(jì)（FTK1000，F(xiàn)TK2000，F(xiàn)TK1450）的線性描述如下：

Power measurement linearity

• 850 nm: ±0.2 dB for power from 0 dBm to -45 dBm, ±0.25 dB for power < -45 dBm.

• 1300 nm, 1310 nm, 1490 nm, 1550 nm, 1625 nm: ±0.1 dB for power from 0 dBm to -55 dBm. ±0.2 dB for power > 0 dBm and < -55 dBm.

同時(shí)光源的穩(wěn)定性也是十分重要的。福祿克SImpliFiber PRO光功率計(jì)（FTK1000，F(xiàn)TK2000，F(xiàn)TK1450）光源文檔性描述如下：

Power output stability

• 850/1300nm source: ±0.1 dB over 8 hours

• 1310/1550 nm source: ±0.25 dB over 8 hours
  
  At 23°C ±2°C (73°F ±3.6°F), after 5 minutes of warm-up time.