118_4416655_Rev06

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Water bottom measurement ___________________________________________________________________________ The offset (water probe bottom position) item WB then becomes: WB = (‘ A ’ + product level) - (nozzle height – ‘ B ’) = 0.016 m (or 0.62 inch or 0.052 ft) Note: If WB is a negative figure then it is possible to have a negative water level reading. Water probe length : The 765 VITO water probe and 766 / 768 VITO combi probe can have different water probe lengths. The actual water probe length can be found from the Model selection code of the probe. This length must be entered in item WP (water probe length). Table 5 – 1 gives an overview: Position 2 Model selection code (765/766/768) Item WP (LD=M) [metres] Item WP (LD=F) [feet] Item WP (LD=I) [inch] Item WP (LD=P) [fractions] A +000.4850 +0001.591 +00019.09 +01’07”02 B +000.9850 +0003.232 +00038.78 +03’02”12 C +001.9850 +0006.512 +00078.15 +06’06”02 Table 5 – 1 Minimum and Maximum capacitance : Factory calibration values for the maximum capacity and minimum capacity are listed on the “CheckList 765/766/768 Final Assembly”, delivered with every VITO probe. The value at VR is the minimum capacity (capacitance measured in air). This is an approximate value and depends on the dielectric property of the stored product. This value needs to be adjusted. The value at VT is the maximum capacity (capacitance measured in water) and needs no adjustement. Calibrating the water probe : Refer to Appendix B for information about calibrating the water probe. Where the water dip is mentioned, please refer to the measured water level at the probe position as described before. Instruction manual VITO Page 38
Water bottom measurement ___________________________________________________________________________ 5.2.2 Water probe settings Item Name Description W2= Protection level 2 Enter protection level 2 VR= Minimum water capacity VT= Maximum water capacity Floating point format; default: +.00000000E+00. Enter the value obtained from the calculations in Appendix B. As an alternative, the value from VR as listed on the “CheckList 765/766/768 Final Assembly” can be used. Floating point format; default: +.00000000E+00. Enter the value from VT as listed on the “CheckList 765/766/768 Final Assembly”. WB= Water probe bottom position Format according to item LD (default: + 000.0000 m) This item gives the offset to the water probe zero point in relation with the tank zero point. Refer to section 5.2.1 how to obtain this offset value. WP= Water probe length Format according to item LD (default: + 001.0000 m) The water probe length (together with the water probe bottom position) is required to calculate the water level. Refer to section 5.2.1 which value needs to be entered. WF= Water level field communication One character: ‘S’ or ‘D’. Only valid with 854 level gauges. This item selects from which source the water level is measured and transmitted in the level record (B-record) to the system. S : from the water probe (VITO water sensor or side mounted water probe) D : from water dip (displacer) Select ‘S’ for 854 the gauges (default: D). WH= Water high alarm Format according to item LD (default: +000.0000 m) With this item a water high alarm set point can be given. When active, the water high alarm condition is signalled on the instrument display in display format K (if display is available). The water alarm information is also transmitted in the water level record (M-record). WL= Water low alarm Format according to item LD (default: +000.0000 m) With this item a water low alarm set point can be given. When active, the water low alarm condition is signalled on the instrument display in display format K (if display is available). The water alarm information is also transmitted in the water level record (M-record). WS= Water alarm hysteresis Format according to item LD (default: + 000.0100 m). The water alarm hysteresis prevents the water alarm to be switched on and off when the water level is around the water high or water low alarm set point. EX Exit Exit protection level Instruction manual VITO Page 39
Page 1: Instruction manual VITO interface a
Page 4 and 5: ___________________________________
Page 6 and 7: ___________________________________
Page 8 and 9: Introduction VITO Interface and ave
Page 10 and 11: Average temperature measurement wit
Page 38 and 39: Water bottom measurement __________
Page 46 and 47: Appendix __________________________
Page 48 and 49: Appendix __________________________
Page 50 and 51: Notes _____________________________
Page 52: Honeywell Enraf Delftechpark 39 262

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