LBXXXA Series USB Powe
™
Product Manual PMA (Power Meter Application)
Revision: 08/02/11
- 12 -
Making Basic Measurements
This manual applies to models LB478A, LB479A and LB480A as well as models LB559A, LB579A and LB589A. All
sensors function identically for CW measurements. The significant difference between these sensors is the ability to
make pulse measurements.
The sections of this manual that focus on pulse measurements apply only to models LB478A, LB479A and LB480A .
These sensors will be collectively referred to as LB4XXA sensors throughout the remainder of this manual. The
LB4XXA sensors can make both CW and pulse (modulation) measurements. The LB559A, LB579A and LB589A will
be collectively referred to as LB5XXA sensors. The LB5XXA sensors can make broadband CW measurements only.
These CW measurements are thermally compensated, true RMS measurements.
Zeroing and Reference Power Calibration
The design of the power sensor does not require zeroing or power calibration and there is no provision for zeroing or
calibration.
NOTE:
While zeroing is not required for any LadyBug sensor, the LB5XXA sensors require time to thermally stabilize.
Little if any warm-up time is required for measurements above -40.0 dBm. However, to make accurate measurements
below -40 dBm the LB5XXA sensor should be allowed to thermally stabilize for one hour.
Setting the Center Frequency
Set the center frequency (GHz) as shown below. The center frequency
must
be set whenever the incoming signal
frequency changes. Measurement accuracy requires the frequency to be set and not doing so can be a significant
source of error. The frequency can also be set by sliding the analog frequency scale pointer just below the active
display. The pointer will change color from blue to red when the center frequency is beyond the measurement range of
the sensor. The pointer is less accurate but more convenient than entering a frequency value. You can also set the
frequency by selecting
Measurement > Set Frequency
from the menu bar (not shown) .
