I do a lot of new residential houses. With the r-410a refrigerant, you have to use sub cooling for your charge to be correct. So - this isn't a tip, but what I use to get the job done right. I use a Fluke 16 Digital Mulitmeter, with a Fluke 80TK Thermocouple Module and a Fluke 80PK-8 Pipe Clamp Probe. This is a temperature pipe clamp that you clamp onto the liquid line and with your gauges right there in front of you, you can get the sub cooling done rather quickly. To finish the job I use my Fluke 62 Mini IR Thermometer to check my supply and return temps. It is a great joy to work with these tools as they are the best in the field that I have used and not the most expensive to keep in your tool pouch.
By Joe Lamere
I use Fluke exclusively for superheat/subcooling measurements with the Fluke 80PK-8 Pipe Clamp Probe together with the Fluke 52 Digital Thermometer. I use the Fluke 80K-40 High Voltage Probe (recommended in Carrier literature) to accurately test electronic air cleaners output voltage (6 Kv-dc).
By David Watson
I bought a Fluke 61 IR Thermometer several years ago, and even though its design has been improved upon, the 61 has not outlived its usefulness. I use it for quick sub heat and sub cooling checks on the refrigerant system, Delta T checks across the evaporator and condenser coils, checking tripping breakers, contactors, compressors, condenser and evaporator fan motors, and bearings for overheating.
By Jason Sims