Choosing a meter for HVAC
Meters used in the HVAC industry are somewhat similar to general purpose meters.
There are, however, some specific needs for our industry:
1. Voltage: AC to 600V
2. Voltage: DC to 300V Must be able to read in 1 millivolt increments
3. Amperage: AC to 300A Must be able to read 1/100 of an amp.
4. Resistance: to 5 megohms Must be able to read 1/10 of am ohm.
5. Must have a continuity beep.
6. Microamps : Must be able to read 1/10 of a microamp.
7. Capacitor tester.
In addition, features that are nice to have but are not absolutely necessary are:
1. NCV (non contact voltage tester) built in to the meter.
2. Led flashlight built in to the meter.
3. Backlit scale.
4. All features in one meter.
5. Auto ranging.
6. Comes with a temperature probe.
7. A setting that eliminates ghost voltages.
8. A surface mount temperature probe
9. Costs $10 (just kidding)
10. A true RMS meter. This feature is becoming more necessary as HVAC equipment becomes more and more electronic.
There are, however, some specific needs for our industry:
1. Voltage: AC to 600V
2. Voltage: DC to 300V Must be able to read in 1 millivolt increments
3. Amperage: AC to 300A Must be able to read 1/100 of an amp.
4. Resistance: to 5 megohms Must be able to read 1/10 of am ohm.
5. Must have a continuity beep.
6. Microamps : Must be able to read 1/10 of a microamp.
7. Capacitor tester.
In addition, features that are nice to have but are not absolutely necessary are:
1. NCV (non contact voltage tester) built in to the meter.
2. Led flashlight built in to the meter.
3. Backlit scale.
4. All features in one meter.
5. Auto ranging.
6. Comes with a temperature probe.
7. A setting that eliminates ghost voltages.
8. A surface mount temperature probe
9. Costs $10 (just kidding)
10. A true RMS meter. This feature is becoming more necessary as HVAC equipment becomes more and more electronic.
What the different brands offer:
Fluke
At left is the Fluke 116. It is a multimeter that incorporates all functions necessary for the HVAC tech except AC amp measurements.
What it has:
AC and DC voltage measurements.
Resistance measurements from .1ohm to 6 megohms.
Audible beep for low resistance continuity.
DC microamp capability to .1 microamp.
Capacitance testing.
Auto ranging.
Has a temperature probe.
It is a true RMS meter.
It has a back light.
It has a loZ setting that will eliminate ghost voltage readings.
This meter has internal surge protection to protect the meter electronics if the meter is set to "ohms" and the probes are placed across a live circuit, the meter will not be damaged. (within reason).
What it does not have:
A clamp ammeter.
No NCV.
No led flashlight.
No surface mount temperature probe.
Click on the pic to go to fluke.com
What it has:
AC and DC voltage measurements.
Resistance measurements from .1ohm to 6 megohms.
Audible beep for low resistance continuity.
DC microamp capability to .1 microamp.
Capacitance testing.
Auto ranging.
Has a temperature probe.
It is a true RMS meter.
It has a back light.
It has a loZ setting that will eliminate ghost voltage readings.
This meter has internal surge protection to protect the meter electronics if the meter is set to "ohms" and the probes are placed across a live circuit, the meter will not be damaged. (within reason).
What it does not have:
A clamp ammeter.
No NCV.
No led flashlight.
No surface mount temperature probe.
Click on the pic to go to fluke.com
Fluke clampmeters
The meter at left is the Fluke 373.
This meter will read ac amps using its clamp function. What it has: Reads AC amps. Reads AC and DC volts. Capacitor tester. Ohmmeter (only up to 6000 ohms).Audible beep for low resistance continuity. It has auto ranging. This meter has internal surge protection to protect the meter electronics if the meter is set to "ohms" and the probes are placed across a live circuit, the meter will not be damaged (within reason).What it does not have: Megohm meter No NCV No led flashlight No surface mount temperature probe. Click on the pic to go to fluke.com |
Both of the above meters are necessary to complete the meter set
Fluke 116-322 kit
The kit on the left contains all the features necessary for a complete set for the HVAC industry. The clampmeter is the Fluke 322 meter which is a meter with less features than the 373 but those features are on the 116 meter included in the kit.
This kit also includes a surface mount temperature probe for sensing tubing temperatures.
This kit has the advantage that it is somewhat cheaper than the 2 above meters purchased separately.
What it does not have:
No NCV
No led flashlight
Click on the pic to go to fluke.com
This kit also includes a surface mount temperature probe for sensing tubing temperatures.
This kit has the advantage that it is somewhat cheaper than the 2 above meters purchased separately.
What it does not have:
No NCV
No led flashlight
Click on the pic to go to fluke.com
Overall view of the Fluke product line
Fluke has the reputation of producing high quality meters that are robust and long lasting. They were the first that I know of to make meters that could be misused (to a reasonable extant) and still survive. I see nothing in the newer products to refute that. I have never had a Fluke product fail me on the job site and I cannot say that for some other meters I have used. Battery life is very good and there are no fuses to blow.
That said they are not perfect. The temperature probe is usually out of calibration by 4 to 10 degrees F and has been so for over 5 years. Changing the probe will not help, the meter is the problem. I think Fluke has lost some control of the manufacturing since the meter assembly has been moved to China. Their meters do not have all the bells and whistles of some other meters and that needs to be improved.
Even with these problems, I am still a "Fluke freak".
That said they are not perfect. The temperature probe is usually out of calibration by 4 to 10 degrees F and has been so for over 5 years. Changing the probe will not help, the meter is the problem. I think Fluke has lost some control of the manufacturing since the meter assembly has been moved to China. Their meters do not have all the bells and whistles of some other meters and that needs to be improved.
Even with these problems, I am still a "Fluke freak".
Fieldpiece
On the left is the Fieldpiece SC76.
This meter is an all in one unit. It has an NCV built in to the unit. Rather than go into everything it has I will say what it does not have. It is not True RMS There is no led flashlight There is no surface mount thermometer. Click on the pic to go to Fieldpiece .com |
On the left is the Fieldpiece SC77.
The difference between the SC76 and the SC77 is the SC77 is true RMS and the readout is backlit. Other than that, they are the same. These meters can be used with all accessory heads that fieldpiece makes. The accessory heads can be purchased for many applications from a micron vacuum gauge to manometer heads. The other option with Fieldpiece is the HS36 stick meter. It will be shown below. Click on the pic to go to Fieldpiece .com |
The stick meter makes it simpler to use the variety of heads available. The fieldpiece products are of high quality and are very robust. I once saw one get caught in a condenser fan blade and it still worked! The central rotary switch looks like could break off easily but I have never seen one break.
If you buy the SC 76 or 77, you can get into the business for a lower price because you only need one meter.
This is both good (lower price) and bad (no backup meter). Any of these meters would be a good choice.
If you buy the SC 76 or 77, you can get into the business for a lower price because you only need one meter.
This is both good (lower price) and bad (no backup meter). Any of these meters would be a good choice.
UEI
UEI has for me somewhat of a checkered past. The products have been poorly made and not well protected.
However, these new meters are better. I even own one and have no problems with it. The 2 meters I would consider are the DL379 and the DL389. Both are all in one meters. The one feature they have that most other meters do not is the dual display. The top reading is amperage as measured by the clamp. The bottom reading can be voltage, resistance, microamps or capacitance. This gives you the ability to take an amp reading while testing voltage. The DL379 is not true RMS. The DL389 is true RMS. Both meters have, in addition to all of the things necessary for the HVAC tech, an NCV, auto ranging and an led flashlight. There is no surface temperature probe. Click on the pic to go to UEI . |
Klein
The MM2300 meter is a true RMS one. It has all the necessary readings for a multimeter. There are fuses in the meter, so thats a negative. It is auto ranging. It also has a backlight. It does not have a surface temperature probe. One feature it has that many do not is a lineal scale on the bottom that shows something like a percentage reading. I do not think it is especially helpful.
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The CL1000 clampmeter is necessary to complete the meter kit with Klein. It has NCV and a flashlight and is auto ranging. It is not true RMS.
The Klein meters are not made by Klein. They have been high in quality and quite robust. You must buy both meters to get all the features needed. Click on the pic to go to Klein tools |
Milwaukee
The Milwaukee 2216-20v1 multimeter has the megohm meter that the clamp meter lacks. It is also is full featured with the exception of a temperature probe. There is a fuse on the amp feature.
These meters are good serviceable meters and appear to be robust. My only experience with these meters is through my students' purchase and use of them. You need both meters for all features. Click on the pic to go to Milwaukee tools |
After reading this page you may see the choice of a meter is a complicated one. Also different people will like different types of meters. The only way to find out what you like is to use the specs I have given and take your best shot. Also meters are changing each year with more features and specs. Your meter is your most valuable tool and can save your life or conversely can get you into terrible trouble. The more experienced tech can sometimes get by with less and poorer quality tools because he has a better understanding of what he is doing. (however, the experienced tech usually has better meters) If you are new to the business, you need to have quality meters as they are more forgiving for the mistakes you will certainly make.