You want to take the diameter of the meter times 10 on the inlet and times 5 on the outlet. For a 1 in. meter this would be 10 in. of straight 1 ft pipe going in and 5 in. of straight 1 ft pipe coming out. If you cannot do this you will not make the meter worthless, but you cut into the accuracy.

Turbine meters can not tell the difference between air and liquid. It just knows the turbine is spinning, so any reading will be inaccurate if air is going through the turbine. Another reason to not put air through a turbine is potential damage. The air will make it spin extra fast, with no liquid for lubrication damage can occur. When the liquid gets there it can hit the turbine like a hammer. It is recommended to slowly bleed the air out of the lines then reset the meter total.

In general you can expect a turbine meter to keep counting below its minimum range, but it will lose some of its accuracy. Normally it will completely stop at ½ of its published minimum flow. For example a ½ in. meter that reads between 1 and 10 LPM will be able to stretch down to around 1/2 a litre per minute. Keep in mind that nothing below the published minimum flow is guaranteed, and not all turbines will give this much extra performance.

The G Series, G2 Series and A1 Series Meters all come with a calibration report. This report is the data of the output of the meter at several flowrate points and will meet or exceed the advertised accuracy of the meter over the recommended flow range. This report should not be confused with a calibration certificate. (If a certificate is needed, request one from GPI.)

Yes, you can purchase a FM Approved Remote Kit (part # 113275-1). You can take the existing display off of your TM, A1 or G2 series meters, and put the remote kit in its place. At the other end of the remote kit is a box that is designed to be panel mounted. The existing display can then be installed on the remote box.