Performance Test And Calibration; Introduction; Equipment Required; Dc Volts Test And Calibration - HP 3478A Technical Manual

4-1. INTRODUCTION

4-2. This section of the manual has the Performance
Tests and Calibration Procedures used to verify the
3478A's accuracy specifications, and to calibrate the
multimeter to those specifications. A summary of the
specifications to which the 3478A is tested and calibrated
is listed in Table 4-1. The complete specifications are in
Table 1-1. All tests and calibrations are made without
removing any instrument 'covers.
4-3. Since Performance Tests are normally performed
after calibration, the tests are included in the Calibration
Procedures. The procedures are set up in such a way
that the Performance Tests can be ignored, if so desired.
Table 4-1. Abbreviated Specifications Table
DC Volts Function (accuracy = ±(% of reading - number of counts))
Range 24 Hour Limits
30mV 0.027 + 35
300mV 0.005 + 4
3V 0.0034 + 2
30V 0.005 + 3
300V 0.0055 + 2
DC Carrot Function (accuracy = ±(% of reading + number of counts)
Range 90 Day Limits
300mA 0 11 + 40
3A<1A 0.14 + 6
3A>1A 1.0 + 30
Ohms Function (accuracy = ±(% of reading + number of counts)
Range 24 Hour Limits
30 0.023 + 35
300 0.0045 + 4
3K 0.0035 + 2
30K 0.0035 + 2
300K 0.0035 + 2
3M 0.0052 + 2
30M 0.036 + 2
AC Volt Function 1 Year Limits (accuracy = ±(% of reading + number of
counts)
Frequency 300 mV Range 3V Range
20Hz 50Hz 1.14 + 163
50Hz 100Hz 0.46 + 163
100Hz 20KHz 0.29 + 163
20KHz 50KHz 0.56 + 247
50KHz 100KHz 1.74 + 882
100KHz 300KHz N/A
AC Current Function 1 Year Limits (accuracy - ±(% of reading + Number of
counts))
Frequency 300mA Range
20Hz 50Hz 1.54 + 163
50Hz 1KHz 0.81 + 163
1KHz 10KHz 0.72 + 163
10KHz 20KHz 0.86 + 163

PERFORMANCE TEST AND CALIBRATION

90 Day Limit 1 Year Limits
0.03 + 41 0.04 + 41
0.0074 + 5 0.02 + 5
0.0059 + 2 0.0188 + 2
0.0074 + 3 0.02 + 3
0.0076 + 2 0.02 + 2
1 Year Limits
0.15 + 40
0.17 + 6
1 0 + 30
90 Day Limits 1 Year Limits
0.0027 + 41 0.034 + 41
0.012 + 5 0.017 + 5
0.011 + 2 0.016 + 2
0.011 + 2 0.016 + 2
0.011 + 2 0.016 + 2
0.011 + 2 0.016 + 2
0.066 + 2 0.078 + 2
30V Range 300V Range
1.14 + 102 1.14 + 102 1.18 + 102
0.46 + 103 0 46 + 102 0.5 + 102
0.26 + 102 0.26 +102 0.33 + 102
0.41 + 180 0.37 + 180 0.56 + 180
1.05 + 825 0.84 + 825 1.26 + 825
10.1 + 3720 N/A
3A Range
2.24 + 163
1.5 + 163
1.42 + 163
1.56 + 163
SECTION IV

4-4. EQUIPMENT REQUIRED

4-5. All the required test equipment for the Performance
Tests and Calibration Procedures are listed in Table 4-2
(Recommended Test Equipment). The equipment used for
the individual tests is also listed at the beginning of each test
procedure.
available, use substitute equipment. A short description of
the required equipment and the critical specifications
necessary to do the test and calibration procedures is in the
following paragraphs.
choosing substitute equipment.

4-6. DC Volts Test and Calibration

4-7. The DC Volts Test and Calibration (DC Volts Function)
requires a very accurate Digital Voltmeter (like the 3456A) as
the Standard. The Digital Voltmeter must be calibrated to its
24 hour dc volts specifications before calibrating and testing
the 3478A (i.e. the 3478A is tested and calibrated within 24
hours after the Digital Voltmeter, used as the standard, has
been calibrated). It is recommended that the Digital Voltmeter
be calibrated in the same temperature environment and leave
it in the environment in which the 3478A is to be calibrated
and tested (e.g. the 3478A's Reference Temperature, see
Paragraph 4-39). In addition to the Digital Voltmeter, a DC
Volts Standard is required to be used as a very stable voltage
source. The following lists the required equipment and
recommended models.
4-8. Digital Voltmeter. The recommended Digital Voltmeter
is an -hp- Model 3456A. The critical requirements are as
follows:
a. Required voltage range is from 30mV to 300V dc.
b. Accuracy and stability requirements in a 24 hour period
is as follows:
±.004% for the 30V and 300V Ranges
±.005% for the 300mV and 3V Ranges
±.025% for the 30mV Range
N,A
4-9. DC Volts Standard. The DC Volts Standard chosen is
a Systron Donner Model M107 Precision Voltage Source.
The critical requirements are as follows:
4-1
If any of the recommended equipment is not
This information may be helpful in
TM 11-6625-3071-14