Klein Tools ET180 Digital Differential Manometer

Yes. The ET180 reads air and gas pressure across a range of +/- 60 inH2O, which is 2.16 PSI at the top end, so it covers the low-pressure manifold and supply readings on gas-fired equipment. It reads in inH2O plus bar, oz/in2, psi, mbar, kPa, inHg, mmHg, kg/cm2, ftH20 and cmH2O, so you can match whatever units the equipment tag calls out. Full scale accuracy is +/-1.5 percent. It is not suitable for anything above 2.16 PSI.

The two ports are tapered stainless steel and accept tubing from 1/8 inch to 5/15 inch, so most common low-pressure silicone or vinyl tubing pushes straight on. Silicone tubing is supplied with the meter, so you can work out of the box without sourcing hose.

Hook one hose upstream and one downstream and switch the meter to Differential mode. The ET180 has three modes, P1, P2, and Differential, so you can read either port on its own or the difference between the two without moving hoses. The hold button freezes the reading when the display is out of sight, and it tracks minimum, maximum and average values for readings that fluctuate.

No. The meter is not insulated. Klein's own warning is to avoid contact with areas where energized conductive elements may be present and to shut off power to the area before taking measurements, with approved eye protection worn. Treat it as a pressure instrument only, not a tool for live electrical work.

Silicone tubing, three AAA batteries and a storage pouch ship with the meter, so nothing else is required to take a reading. It runs on 3 x AAA cells with a low battery indicator and an auto power off to stretch battery life.

One tech can. There's a strong magnet on the back of the housing, so the meter sticks to ductwork or a unit cabinet while you place hoses. The LCD is backlit for reading in a dark crawlspace or plenum, and at 7.2 oz (202 g) the magnet has very little to hold.

Operating temperature is 32 to 122 degrees F (0 to 50 degrees C), so it works on a hot summer rooftop but not in below-freezing conditions. The housing is ABS with stainless steel ports.

The ET180 conforms to EN 61326-1:2013 and EN 61326-2-3:2013, and is CE and UKCA certified. That covers electromagnetic compatibility for electrical measuring equipment.

Yes, it reads down to -60 inH2O as well as up to +60 inH2O, so negative-pressure readings on the return side or a draft check are within range.

It's a handheld the size of a large phone: 6.19 x 2.47 x 1.38 inches (15.7 x 6.3 x 3.5 cm) as listed, and it comes with its own storage pouch. Packed weight is 0.37 lbs.

Klein lists the ET110 and ET120 combustible gas leak detectors, the ET160 receptacle tester, the CL320 clamp meter and CL320KIT, the IR07 and IR10 infrared thermometers, and accessories 69142, 69144 and 69410 as companions to the ET180. A common HVAC kit is the manometer for static and gas pressure, a clamp meter for amp draw, and an IR thermometer for supply and return temperatures.

No. The Klein Tools digital differential manometer is sold as a single model, part number ET180. There are no finish, range or port variations to specify.