Environment

NI DMMs use precision components whose performance can be adversely affected by operation outside the specified limits. For more information, refer to the Environment section in the specifications document of your device at Related Documentation.

For best performance:

• Ensure that the ambient temperature is between 0 ºC and 55 ºC (NI PXI-4060/4065 and NI PXI-4070/4071/4072), 0 °C and 45 °C (NI USB-4065), or 0 °C and 40 °C (NI PCI/PCIe-4065 and NI PCI-4070).
• Follow standard metrology practices as you would for any ppm-level measurements.
• Use a chassis that has a well-designed cooling system, allowing the DMM to stay cool. All NI PXI chassis meet this requirement.

Operating the NI 4070/4071/4072 outside the specified operating temperatures can increase bias currents in the electronic components, increase noise, accelerate drifts, and decrease product life. Beyond the maximum specified operating temperatures, the DMM's circuits perform differently than during the factory calibration, resulting in additional measurement errors which may not be accounted for by the Tempco specifications.

Note  To ensure PXI, PCI, and PCI Express DMMs operate at peak performance, refer to Chassis for recommendations. To ensure USB DMMs operate at peak performance, refer to USB System Considerations for recommendations.

Operating under high humidity (>80%, >35 ºC) or dusty conditions can cause leakages between circuit components to increase and result in additional measurement errors, especially in resistance measurements above 100 kΩ.

NI used a highly accelerated life test (HALT) to verify the operation of the NI 4070/4071/4072 during severe environmental and operational stresses beyond normal shipping, storage, and operational levels.

You can operate the NI 4070/4071/4072 at temperatures below 0 ºC (down to -10 ºC) for short periods of time. The NI PXI-4070/4071/4072 operates at about 10 ºC higher than the incoming air in the PXI module. Operation above 55 ºC could induce gain errors due to the precision reference temperature control dropping out of equilibrium. You can measure the temperature of the DMM using the onboard temperature sensor.

NI designed the NI 4070/4071/4072 with robust built-in precision voltage and resistance standards. These standards and the self-calibration function improve the performance of the NI 4070/4071/4072 at the extremes, even beyond the capability of most other DMMs. Regardless, you should always ensure appropriate environmental requirements are met.