"The most comprehensive source for Automotive Tools & Equipment" Model: 14777 Compact Electronic Vacuum Gauge How long should a vacuum pump be left on the system for complete moisture removal? Here's the answer - in a package small enough to fit in a shirt pocket. Robinair's 14777 electronic vacuum gauge is just 2-1/2" x 3" in size, but accurate enough to clearly indicate when the system is free from moisture and ready for recharging. Specifically designed for use with high vacuum pump, the 14777 measures to 10 microns. The digital display reads in ranges beginning with 20,000 microns. As the vacuum pump continues to pull down, the instrument registers in ever smaller segments - from 1000s of microns to segments of 500s to 50s.The ultimate reading is 10 microns. Clearly Shows Vacuum Level - The display is an easy-to-read LCD type with readout showing the current vacuum level. 6' Lead for Service Flexibility - A thermistor measuring vacuum level is attached to a 6 foot long lead that plugs into the instrument. You can hang the gauge in a location that's convenient for you to monitor vacuum level. Because the thermistor with lead is removable from the unit, it can be easily replaced, if necessary. Mounting Magnet - Use the heavy duty magnet strip on the back of the unit to attach it to the A/C or refrigeration unit. You can position the 14777 where it's easy to read the LCD. Takes the guess work out of evacuation Without a vacuum gauge, you risk not dehydrating the system completely and causing operational problems down the road. Or you waste time by running the vacuum pump long after evacuation is completed. Because the instrument is sensitive to water vapor, it gives a reliable indication of the actual vacuum level within the system - no more wondering if the system is ready for charging. Hassle-Free Operation The 14777 is simple to use - just connect the thermistor lead to an access port on the system or off the inlet tee on the vacuum pump. Press the on/off button, then start the vacuum pump. For large systems, you can save battery life by running the pump for a few minutes, then turning the vacuum gauge on - all it takes is the push of a button. Pro Tips: When reading vacuum, remember that the location of the vacuum gauge tube will affect the reading. the closer the gauge is to the vacuum pump, the lower the reading will be. Conversely, if you take the reading at the line far away from the pump, the reading will be on the high side. The way to get the most reliable reading is to isolate the vacuum pump using a vacuum valve assembly. Allow the pressure to equalize throughout the system, then take a final reading. A reading that's too high is a good indication of moisture in the system; continuing to evacuate will likely pull the system into a deeper vacuum. IF the pressure will not equalize, you probably have a leak which should be repaired. SPECIFICATIONS Power Supply One 9V battery (included) Vacuum Fitting 1/4" MFL Length of Lead 6 feet (8.3 m) Dimensions 2-1/2" W x 3" H x 1" D (6.35 cm x 7.62 cm x 2.54 cm) Related "Robinair" Product Information Model 14777 Compact Electronic Vacuum Gauge - Product Page AC Vacuum Pumps - Index Page Full Product Listing - Index Page