NF WF1945B, Instruction Manual

Page: 163 / 188

WF1945B
7-5
7.3 Performance tests
„
Performance tests
Performance tests are an important part of preventive maintenance and serve to prevent serious
deterioration of the equipment performance.
Conduct these tests at incoming inspection, routine inspection, following repair and whenever performance
needs to be confirmed.
When specifications are not met in performance tests, service is required. Contact the dealer.
„
Preparatory checks
Check the following before testing performance.
z Power source voltage is within specified range.
z
Ambient temperature is 23
±
5
°
C.
z
Ambient relative humidity is within 20 to 70 % RH.
z Condensation is absent.
z
Allow at least 30 minutes warm up.
„
Test preparation
z
Signal cables are 50
Ω
coaxial, RG-58A/U or thicker, less than 1 meter length and fitted at both
ends with BNC connectors.
z
Where items call for 50
Ω
termination, set the input impedance of the connected instrument to 50
Ω
.
Where this is impossible, use a 50
Ω
feed through terminator at the test instrument input.
z Initialize the settings for each test item (
SYSTEM
→ [PRESET]), set the output on (key internal
LED lights according to
OUTPUT
ON/OFF
) and the item to be changed is indicated.
„
Frequency accuracy
Connection: Use coaxial cable to connect FUNCTION OUT to a universal counter (50
Ω
termination).
Setting:
Initialize, then set frequency to 1 MHz and amplitude to 20 Vp-p/open.
Measurement: Measure frequency with the universal counter.
Judgment: Normal if within
±
5 ppm (999.995 to 1.000005 MHz) (when shipped)
However, since aging may occur with up to
±
3 ppm/year, deterioration up to
±
8 ppm
(999.992 to 1.000008 MHz) may have occurred if one year has passed since shipment.