Originally Posted by 32quarters
You have a gauge reading metric units: mmHg and MPa.The gauge should show which measurement units apply to each scale. These are usually near the zero or near the highest measurement. Common measurement units are inHg, mmHg, and kPa. As you noticed there are generally two scales on the gauge, an inner and an outer.
The gauge ranges for a vacuum gauge are:
0 to -30 for inHg (inches of mercury)
0 to -760 for mmHg (millimeters of mercury)
0 to -100 for kpa (thousands of pascals)
0 to -0.1 for Mpa (millions of pascals)-5inHg is about -125 mmHg which is about -0.017 Mpa or -17kpa
And also:
-30inHg = -760 mmHg = -100 kpa = -0.1 Mpa
Thank you man, appreciate it. What I’ve realised is the gauge doesn’t start at 0, its sitting at .04 mpa/ 300 mmhg, faulty, so I’ll have to add on to that.
Thanks again.