REVIEW: Digi-Cool AK900 DRSA
All I have to say is one word...."WOW."
Prior to performing this review I had several conversations with the inventor and owner of DC, Doug Lockhart. Doug is a class act and a dedicated professional. All this is apparent in the quality of the AK900. From the knobs to the screen, everything seems precisely chosen for optimal performance. I think what makes this DRSA different from others is that it was invented and designed by a technician. Not an engineer.
I opened the DC box and inside was a digital gauge apparatus, manifold, manifold hook, manual, CD, blue/red wire velcro pipe temp sensors, and a tire gauge. In the picture you will see two additional sets of temp sensors. The scissor clamp style and large head rubber velcro pipe temp sensors are extra accessories.
In removing them from the box, the first thing I noticed size and weight. They're not very heavy but seem well built/sturdy. The digital gauge apparatus is made of heavy plastic construction and covered with a snug fitting rubber boot. The thing that makes the DC gauges unique is the fact that you fit them almost any manifold. It fits right on a few, like the Sherman and YJ41 but other manifolds would require a few fittings.
Turning on the unit, I noticed a large display with lots of info. This has to be my favorite feature, the amount of info displayed on one screen without any toggling. It has bright green backlight. The interface is fairly intuitive. I did have the reference the manual in order to figure out how to turn on the backlight.
Digi-Cool uses sealed thermistors for their pipe temp sensors. Testo and DC are the only ones who use this type. Others use "K" type which are susceptible to stray/EMI/induced voltages which could drastically throw off temp readings.
The pipe clamps have a large jaw opening. Easily could fit 1"1/8 or 1"1/2. The Velcro straps are huge and will fit up to a 3" pipe! The only draw back I have to these sensors is the reaction time. The reaction time is slower than other sensors for DRSA's. Not real slow, just not super fast like the SMAN'S. But I would take the slower accurate DC's sensors over faster and possibly inaccurate.
The AK900's use a 200 psia transducer on the low side and a 600 psia transducer on the high side. With 0.5% accuracy, that makes the DC's pretty dog gone accurate! Some of the other DRSA use 550 psia on low and 750 on high. Another of the great features is dynamic offset bar @ the top of the display. Early this week, I pressurized a split system with nitrogen to find a leak and the bar graph was a huge help in watching the pressure decrease. It is a valuable diagnostic tool. The bar graph updates 4 times a second and makes even the tiniest fluctuations easy to see.
The actual manifold is unique in itself. It is ball valves. A quarter turn and each knob is wide open. I love this. I've gotten spoiled and don't want to go back to a traditional style manifold. The manifold also has sight glass.
Overall, I have a new primary set of gauges. They're now hung closet to the van door so I use them daily on every call. They're built tough as nails and work with pinpoint accuracy. I don't doubt the durability one bit. I created a list of good and bad features below.
1. Display information
3. Ball valve manifold
4. Bar graph
5. Pipe temp sensor size
1. Sensor reaction time.
I couldn't think of any other "bad" features. I've heard about DC for many years via this site. Now that I've finally got to work with these, I'm a believer too! I also want to note, DC's customer service is superb and help make the great product even better.
I hope this helps someone in the market for a new DRSA (Digital Refrigerant System Analyzer). I will be reviewing the Testo gauges soon as well as several other tools including Blu-Vac, Nylog, toolbags, dual manometers, and a thermal imager.
Brent A. Ridley
[Sorry for the picture being sideways. I haven't figured out how to rotate them (if possible]