Testo® 550 Digital Gauge Manifold

    I was a wee lad when my dad first showed me how to use a refrigeration gauge manifold. Of course he explained the instrument and the inner workings of the refrigeration system in detail many times, I had no idea what he was talking about. Working mainly during the hot summers in Southern California gauges and a good meter became the go-to for every no-cooling service call and in time I learned the science, and art, of refrigeration systems. The problem with gauges has always been the same, they're delicate testing instruments that are thrown in that back of a service truck, expected to last years, and be accurate. I tried to hang them from something, installed protective covers around them, adjusted them frequently and in the back of my mind often wondered if their reading was accurate. I didn't realize how limited this experience was until I ordered our first Testo® 550 Digital Gauge Manifold.

    Before I even set eyes on the gauge manifold I was impressed by the substantial plastic case the system is housed in. I always say every good instrument needs a case, and the case needs to be big enough to include all the parts and pieces, and a few things you didn't think of, Testo® seems to agree. Opening the case reveals the Testo 550 3 port- 2 valve digital manifold with integrated hanger-hook, two clamp-on temperature probes for pipes from 1/4" to 2-3/8" and batteries. I purchased a new set of refrigerant hoses to complete the setup.

    After installing the 4 AA batteries I started up the unit and checked out the interface. The on-board programming includes 34 refrigerant profiles for automatic pressure-temperature calculations and settings for superheat and subcooling using the included temperature probes. You can easily change the display to read suction and discharge pressures along with pressure/temp conversion for a given refrigerant (no temp probe), or measured temperature, or superheat/ subcooling. Optional accessories include a pipe wrap probe (for lines up to 3"), air probe and a waterproof surface probe.
    Using the Testo 550 in the field is a game changer. Once you look at a set of digital gauges your old analog set will seem like a fragile toy. From charging units to pulling a vacuum, the functionality of the Testo® 550 makes refrigeration testing and troubleshooting easier and more important, precise.