The Testo 523 is a good instrument but is costly. It can readout superheat and subcooling occurring in a system but is unable to output what the targeted superheat should be based on load conditions. It is also redundant because most service technicians already have temperature instuments and guages. If superheat and subcooling calculations with readout for corresponding line temperature and system diagnostics is what you are looking for go to exactcharge.com to view a calculator built specifically for our industry. It is able to be loaded onto a Palm PDA and you can purchase the Palm Zire 22 that will run software for around $90.00. It should be available for Pocket PC PDA soon. Of course, I am biased since I am creator of this new product but I would encourage you to go to website and check it out for yourself.
I would agree with you 100%. There is no substitute for education and field experience. Any tool is only as good as the individual who is using it and that is also true for the ExactCharge Calculator. I designed and developed the calculator only as an aid to help assist a qualified refrigeration mechanic. It is capable of many more functions that are not available in the Testo 523, or Digi-Cool manifolds such as displaying targeted superheat based on indoor wet bulb,indoor dry bulb,and outdoor ambient and correlating that data into required suction line temperature for proper superheat charging and also includes a duct sizing calculator and a diagnostic assistant text screen. I very much appreciate your input. Thanks so much.
I am not trying to hijack this thread, but I would just like to add something.
On my "wish list" of things, I would desire a series of tools which utilise the Palm or other such device, to enable open architecture programs to be developed and used for our benefit.
One such tool would be a set of gages which tied in with the PDA and used inputs from temp sensors. Like the Testo but not proprioritary.
Another such tool would be a treasure hunter's metal detector. I envision a unit built using a PDA interface which would be adapted to the latest technology of "descrimating" ... I dont even have the right word to describe this, at this moment.
Oh well ... you maybe get the idea.
Something like this would enable the user to keep their tools for a much longer period of time and NOT have it grow obsolete.
The applications for incorperating PDA "brains" into everyday systems is unlimited.
Years ago, for example, when I was doing a chain of C stores, I wanted to see them incorperate monitoring into each store.
So the tech could know BEFORE it was too late that there is a problem with the a/c or walk in box.
But the cost of each store being retrofitted with a modern ems or simple monitoring system would be cost prohibitive. So the bean counters used to say.
But using a PDA as the main brain and docking this into a mini station which would land all the sensors, a dozen perhaps ... using open architecture for the program itself ... and simply having this device output to an audible alarm which store personell would NOT be able to shut down ...
If you are going to measure amperage get a meter that reads true RMS. Non true RMS meters read at a lower amperage. Not a good thing.
Got that TestoKool 523 last October. One of the menus it calculates and displays the superheat or subcooling in real time. No checking the pressure and the temperature then having to go to chart if the mechanical gage doesn't display the scale for the refrigerant on the system you're testing. Accuracy of this gage is supposed to be + - 0.5 percent. Most mechanical bourdon gages could have an accuracy of 2 - 3 percent depending upon the range. At 250 psi at 2 percent that's 5 psi deviation it could actually be anywhere from 245 to 255. At 3 percent that's a 7.5 psi deviation.
The TestKool with a 0.5 percent deviation that's only a 1.25 psi difference.
It can also data log the systems pressures.
It also has a leak test mode that reads out in psia. With readings in hundereths of a psia and makes temperature corrections for the nitrogen.
MechAcc, does this give us "bragging rights"? being accurate!
guys are asking "Why spend the big bucks?"
most of the 40K PLUS members here work for other people. So $600 is a lot of moola!
And their employers are NOT demanding better accuracy from them. They are simply demanding fewer callbacks and better diagnostics and more thurough repairs.
Now how will using a set of testo gages acheive any or all of the above criteria?
I like the TestoKool because if I am doing a changeout or a startup or just a plain checkout I know the meter is accurate. The superheat or subcooling is automatically calculated. If the system nameplate calls for an 8 degree subcooling for a txv you can slowly add or recover the system charge till you get the 8 degrees. But first set the proper airflow for the tonnage on air conditioning. The only thing that would be easier for everyone is if the manufacturers used Lennox's approach method for charging.