©
National Instruments Corporation
9
NI 446X Calibration Procedure
Test Equipment
Table 1 lists the instruments NI recommends for calibrating the NI 446
X
.
If the recommended instrument is not available, select a substitute
calibration standard that meets the given specifications.
Test Conditions
Follow these guidelines to optimize the connections and the environment
during verification and adjustment:
•
Keep connections to the NI 446
X
short. Long cables and wires act as
antennae, picking up extra noise that can affect measurements.
•
Use a 50
Ω
BNC coaxial cable for all connections to the device.
•
Keep relative humidity between 10 and 80%, noncondensing, or
consult the device documentation for the optimum relative humidity.
•
Maintain the temperature between 18 and 28 °C, or refer to the device
specifications for the optimum temperature range.
•
Allow a warm-up time of at least 15 minutes to ensure that the
measurement circuitry of the NI 446
X
is at a stable operating
temperature.
•
Allow a warm-up time for all the instruments and equipment,
according to the manufacturers’ instructions.
Table 1.
NI 446
X
Calibration Equipment Specifications
Instrument
Critical Specifications
Suggested Model
Calibrator
DC Voltage Range: 1 V, 10 V
DC Accuracy: ±300
µ
V
*, †
, ±3 mV
*, †
Fluke 5700A
Function Generator
Frequency Range: 1 kHz–10 kHz
Frequency Accuracy: ±2 ppm
†
Voltage Range: up to 9 V
pp
HP/Agilent 33250A
Digital Multimeter
DC Voltage Range: 100 mV, 1 V, 10 V
DC Accuracy: ±100 ppm
†
NI 4070
*
±300
µ
V on 1 V range, ±3 mV on 10 V range.
†
This specification contains the initial accuracy and any drift due to temperature and time.