Fluke 561 user manual Typical Measurements, Measuring Dewpoint Temperature

561HVACPro

Users Manual

Table 3 lists recommended Fluke temperature probes for use with the Thermometer:

	Table 3. Recommended Temperature Probes
Probe	Usage
	The piercing probe is the most versatile option. Good for checking air temperature in
80PK-25	ducts, surface temperature under carpets/pads, liquids, thermometer wells, vent
	temperatures, and for penetrating pipe insulation.
80PK-1	The general purpose bead probe is an alternative, for quick, accurate surface
	temperatures and air temperatures within ducts, vent temperatures.
	Pipe clamp probes (2) are essential for tracking continuously changing temperature
80PK-8	differentials on hydronic tubing and pipe loops, and good for quick, accurate
	refrigerant temperatures.
80PK-26	The tapered probe is a good general-purpose gas and surface probe, with a good
	length and low mass tip casing for faster reaction to surface and air temperatures.
	The insulation piercing probe provides a sharp tip to pierce pipe insulation and flat
80PK-9	probe tip for good surface thermal contact, air temperatures within ducts, and vent
	temperatures.

HOLD

The display will remain activated for 7 seconds after the trigger is released. HOLD appears in the upper middle of the display. When the trigger is pulled again, the Thermometer will begin measuring in the last function selected.

Typical Measurements

This section describes a variety of measurements often performed by HVAC technicians. The backlight and laser are on whenever you are making readings with the Thermometer.

Measuring Heating/Cooling Duct Insulation Jacket Temperature

1.Press Dand then press Ato select an emissivity setting.

•HI emissivity for vinyl or PVC jacketed insulation

•LO emissivity for foil faced insulation

Note

Alternately, place black electrical tape on jacket surface. Scan to compare tape and insulation jacket temperatures. Adjust emissivity so insulation jacket temperature is closest to tape temperature.

2.Connect the thermocouple probe. The probe hangs in the air to measure ambient air temperature in order to compare the temperature differential. Temperature deviation between the insulation jacket and ambient air temperature indicates leaky or ineffective insulation.

3.Scan the insulation jacket temperature.

Measuring Dewpoint Temperature

The temperature of the duct insulation jacket at any single point is a critical temperature. If jacket temperature reaches dewpoint temperature, condensation will form.

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