Specifications
8
Agilent U1251A/U1252A User’s and Service Guide
159
[1] Input impedance: >1G
Ω
for 50 mV to 1000 mV ranges. For U1251A, input
impedance is 10 M
Ω
(nominal) for 5 V to 1000 V ranges. For U1252A, input
impedance is 10 M
Ω
(nominal) in parallel with 1.1 M
Ω
at dual display.
[2] The accuracy could be 0.05 %+10 for U1251A and 0.05 %+5 for U1252A. Always
use NULL function to zero out the thermal effect before measuring the signal.
[3] The accuracy of 500
Ω
and 5 k
Ω
is specified after NULL
function, which is used
to subtract the test lead resistance and the thermal effect
[4] For the range of 50/500 M
Ω
, the R.H. is specified for <60 %.
[5] The accuracy is specified for <50 nS and after NULL function with open test
lead.
[6] Always use NULL function to zero out thermal effect with open test lead before
measuring the signal. If NULL function is not used, an additional 20 counts
needs to be added to the DC current accuracy. Thermal effect could occur due
to the following:
• Wrong operation to measure the high voltage of 50 V to 1000 V for resistance,
diode, and mV measurements.
• After battery-charging has completed.
• After measuring a current greater than 440 mA, it is suggested that the meter
be left to cool down for twice the measuring time used.
[7] Current can be measured up to 10 A continuously. An additional 0.5 % needs to
be added to the specified accuracy if the signal measured is in the range of 10 A
to 20 A for 30 seconds maximum. After measuring a current of > 10 A, leave the
meter to cool down for twice the measuring time used before application of low
current measurement.
Summary of Contents for U1251A
Page 34: ...34 Agilent U1251A U1252A User s and Service Guide 1 Getting Started Tutorial...
Page 116: ...116 Agilent U1251A U1252A User s and Service Guide 5 Maintenance...
Page 120: ...120 Agilent U1251A U1252A User s and Service Guide 6 Accessories...
Page 156: ...156 Agilent U1251A U1252A User s and Service Guide 8 Specifications...
