Fluke 279 FC, Руководство по калибровке

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279 FC
Calibration Manual
10
2. Use a dry gas for the purge.
The gas should have a dew point below -15 °C. Fluke recommends nitrogen or dried air. If the gas contains any
water vapor or ice, moisture will form on the target. Use a relatively low flow rate of 2.4 to 4.8 liters/min
(5 CFH to 10 CFH) for the purge.
Ice Buildup on the Target
If a small amount of ice forms:
1. Place the cover back on the target and allow the purge gas to sublime the ice.
2. If more ice forms or a purge is not available, change the instrument set-point to a temperature equal to or greater
than 50 °C with the target uncovered.
3. Allow all ice to melt and all water to dry before returning target to use.
W  Caution
DO NOT wipe the target.
IR Temperature (IR Camera) Below Dew Point
Note
For IR temperature settings below dew point, do not leave the target uncovered for
more than 5 s, since it can cause ice to form on the target. Temperature measurements
above dew point do not require the use of cover.
To make measurements below the dew point:
1. Put the target cover in place.
2. Adjust the set-point to the desired temperature and allow the instrument to stabilize at that temperature.
3. Set IR calibrator emissivity setting to 0.95 to match the emissivity of the Multimeter IR camera settings.
4. Turn the control knob on the Multimeter to IR CAMERA .
5. Warm up the Multimeter for 10 minutes.
6. Remove the target cover when the target stabilizes.
7. Place the Multimeter 20 inches (51 cm) from the black body as shown in Figure 3.
8. Compare the indication on the Multimeter display with the display reading limits in Table 3.
9. Replace the target cover.
IR Temperature (IR Camera) Above Dew Point
To make measurements above dew point.
1. Remove the target cover.
2. Adjust to the set-point temperature and allow the instrument to stabilize at that temperature.
3. Place the Multimeter 20 in (51 cm) from the black body. See Figure 3.
4. Compare the indication on the Multimeter display with the display reading limits in Table 3.
If the display indication falls outside of the range shown in Table 3, repair is necessary.