TDP-S / TDP-D TDP-S TDP-D Pressure sensor. Enables you to control Pressure sensor, with display. Enables the pressure in the fan inlet. you to control the pressure in the fan inlet. Model Electrical Maximum Ø Voltage IP Pressure Dimensions supply power Connector Protection range LxWxH (VA) (mm) (mm) TDP-S 0-10 V / 4-20 24VAC-24VDC 4 6,2 mA IP54 0-2500 Pa 75x36x80 TDP-D MEASURING DEVICE TO GET AIR VOLUME DATA The definition of the volume flow follows through the measurement of the differential pressure in the fan inlet. The are 4 pressure probes positioned in each inlet cone, the pressure probe are connected with a PVC tube. Each size of fan was measured and the calibration curves determined. Based on the curves measured the following calibration factors (k-factor) can be used: Fan-type k-factor Fan-type k-factor BPH 225 50 BPH 500 254 BPH 250 64 BPH 560 330 BPH 280 79 BPH 630 410 BPH 315 100 BPH 710 526 BPH 355 128 BPH 800 667 BPH 400 158 BPH 900 855 BPH 450 209 BPH 1000 1068 The calculation of the volume flow is made according to the following formula: V = k * √Δρ [ m/h ] 3 This relation applies for the density ρ = 1,205 [Kg/m]. 3 At density deviating from 1,205 [Kg/m3] the following correction can be made: Vρ = V1,205 * √ 1,205 / ρ Where: V = volume flow at ρ = 1,205 Kg/m [m/h] 3 3 Vρ = volume flow at density ρ [m/h] 3 ρ= density 1,205 Kg/m 3 ≠ Δρ = differential pressure at the fan inlet (difference between fan inlet and suction chamber) [Pa] The flow rate of the fan in operational conditions may be simply read on the cali- bration chart for the relevant fan size, plotting on the chart the pressure value read by the probe. Example: Consider to use an BPFM 280, rotating at 3550 rpm, with a total pressure of 1000 Pa. The flow rate is about 3.000 m³/h. From the manometer connected to the pressure probe system you will read 1275 Pa. When entering this pressure on the calibration chart pressure axis, at the inter- section with the BPFM 280 calibration curve, a value of 3000 m³/h will be read on the flow rate axis. If the same fan is running at a different speed but with the same flow rate, the pressure probe system will again read ρ = 1275 Pa. 44