Lindab FMI Insert Flow Gauge Instruction Manual
Description
Insert flow gauge FMI is a calibrated orifice plate that can be installed in circular ducts where it is necessary to measure the volume flow. The pressure over the gauge is taken from the two nipples, and the volume flow is determined using the diagram or the accompanying curve constants.
FMI can be installed after duct installation and also in exist- ing systems.
Order code
Dimension
| Ød1 mm | Ød2 mm | A mm |
| 80 | 35 | 90 |
| 100 | 43 | 90 |
| 125 | 53 | 90 |
| 160 | 63 | 90 |
| 200 | 83 | 145 |
| 250 | 103 | 145 |
| 315 | 116 | 145 |
| 400 | 151 | 180 |
| 500 | 191 | 265 |
| 630 | 241 | 265 |
Technical data
The Volumeflow (q) can be calculated from the following formulas:
q = k1√ Δp [m3/h] q = k2 √ Δp [l/s
| Ød1 [mm] | K1 [m3/h] | K2 [l/s] |
| 80 80 | 11.4 11,4 | 3.18 3,18 |
| 101000 | 18.178,7 | 55.,2200 |
| 121525 | 29.279,7 | 8.25 |
| 160 | 51.1 | 14.20 |
| 200 | 80.3 | 22.30 |
| 250 | 124.0 | 34.50 |
| 315 | 211.0 | 58.50 |
| 400 | 346.0 | 96.00 |
| 500 | 544.0 | 151.00 |
| 630 | 875.0 | 243.00 |
Materials and finish
Materials: Galvanised steel and aluminium
Other colours are available. Please contact Lindab’s sale department for further information.
Technical data
Pressure loss – Sound effect
The diagram shows the current pressure loss as a function of the volume flow and A-weighted sound effect level LWA dB(A) at duct. Frequencyrelated sound effect at duct is shown in the table below.
Insert flow gauge
Technical data
Pressure loss – Sound effect
The diagram shows the current pressure loss as a function of the volume flow and A-weighted sound effect level LWA dB(A) at duct. Frequencyrelated sound effect at duct is shown in the table below.
Measurement accuracy
The length of the straight section of ducting required as a minimum to limit the method error to 5% or 10% respectively
is shown in the chart, (d1 is nom. duct dimension).
*) “Tee-Piece” here means a circular joint consisting of a Tee- piece or an attachment.
| Velocity app. 5 m/s | Velocity app. 7,5 m/s | Velocity app. 10 m/s | ||||
| dim | Centre frequency [Hz] | Centre frequency [Hz] | Centre frequency [Hz] | |||
| Ød1 | 125 250 500 1K 2K 4K | 8K | 125 250 500 1K 2K 4K | 8K | 125 250 500 1K 2K 4K | 8K |
| Flow 90 m3/h (25 l/s) | Flow 135 m3/h (37,5 l/s) | Flow 180 m3/h (50 l/s) | ||||
| 80 | 45 42 37 28 18 13 | 12 | 53 48 44 37 27 21 | 19 | 59 53 50 44 36 31 | 27 |
| Flow 140 m3/h (39 l/s) | Flow 210 m3/h (58 l/s) | Flow 280 m3/h (78 l/s) | ||||
| 100 | 43 40 35 27 19 14 | 9 | 53 48 44 36 28 23 | 18 | 62 55 51 44 37 33 | 30 |
| Flow 220 m3/h (61 l/s) | Flow 330 m3/h (92 l/s) | Flow 440 m3/h (122 l/s) | ||||
| 125 | 47 41 34 27 20 15 | 13 | 55 50 44 36 30 26 | 21 | 62 57 52 45 41 38 | 31 |
| Flow 360 m3/h (100 l/s) | Flow 540 m3/h (150 l/s) | Flow 720 m3/h (200 l/s) | ||||
| 160 | 46 39 33 27 21 16 | 13 | 55 48 42 36 31 26 | 21 | 62 56 51 44 40 37 | 30 |
| Flow 540 m3/h (150 l/s) | Flow 810 m3/h (225 l/s) | Flow 1080 m3/h (300 l/s) | ||||
| 200 | 42 36 31 24 18 20 | 12 | 49 46 41 34 29 29 | 23 | 55 55 49 44 40 37 | 35 |
| Flow 880 m3/h (244 l/s) | Flow 1320 m3/h (367 l/s) | Flow 1760 m3/h (488 l/s) | ||||
| 250 | 47 38 31 28 24 22 | 18 | 51 46 40 37 34 32 | 29 | 57 52 47 45 43 42 | 42 |
| Flow 1400 m3/h (389 l/s) | Flow 2100 m3/h (583 l/s) | Flow 2800 m3/h (778 l/s) | ||||
| 315 | 42 35 31 28 24 22 | 15 | 50 43 39 37 33 32 | 26 | 55 50 46 45 42 42 | 39 |
| Flow 2200 m3/h (610 l/s) | Flow 3300 m3/h (920 l/s) | Flow 4400 m3/h (1220 l/s) | ||||
| 400 | 45 41 34 33 30 26 | 16 | 54 48 43 41 39 36 | 28 | 61 53 50 48 46 45 | 42 |
| Flow 3500 m3/h (792 l/s) | Flow 5200 m3/h (1444 l/s) | Flow 7000 m3/h (1944 l/s) | ||||
| 500 | 38 34 31 30 28 25 | 17 | 48 44 41 40 38 35 | 27 | 58 54 51 50 48 45 | 37 |
| Flow 5600 m3/h (1556 l/s) | Flow 8400 m3/h (2333 l/s) | Flow 11200 m3/h (3111 l/s) | ||||
| 630 | 38 33 31 31 28 26 | 22 | 48 43 41 41 38 36 | 32 | 58 53 51 51 48 46 | 42 |
