Bird Technologies 4421 - Manual (Page 22)

Bird 4421 RF Power Meter
10
Error Codes
The Bird 4421 displays error codes when the RF power is either below the
selected range (underrange) or above the selected range (overrange). Table 4-1
displays the error codes and Table 4-2 lists the function limits.
Table 4-1 Error Codes
Table 4-2 Function Limits
Audible Warning
If the RF power level exceeds 120% of the power sensor’s maximum power
capability, the power meter will sound a warning buzzer.
Symbol Explanation
Value greater than overrange limit of function
Value less than underrange limit of function
Function Limit Error
FWD, RFL Power > 199.9% of full scale or 120% of
top range Overrange
FWD dBm, RFL dBm Power > 120% of full scale Overrange
Power < 3% of low range Underrange
SWR FWD < 20% of low range Underrange
FWD – RFL = 0 Overrange
Return Loss FWD < 20% of low range Underrange
RFL < 20% of low range Underrange
Return Loss > 40 dB Underrange