... negative pressure of liquid, gas or vapor not corrosive to copper, steel and alloy, and sends signal or ... '',150mm=6''. 4. Measurement range: From -0.1 to 70Mpa 5. Dial plate: Single or dual scale (psi ... negative pressure of liquid, gas or vapor not corrosive to copper, steel and alloy, and sends signal or ... brass Aluminum PC lens, glass lens Electro connecting pressure gauge/Meter/Manometer for boiler