You need to subtract the rate of change of the tank level (dL/dt) from the outflow rate to give you the inferred inlet flow rate measurement. Best Regards, Ken Heywood, Marketing/Project Consultant Process Control Services, Inc. 401 Industrial Drive Plymouth, MI 48170-1885 Business Phone: (734) 453-0620 Mobile Phone: (508) 241-2040 Text Message: 5082412040@xxxxxxxxxxxxxx (110 character limit) PCS Web: http://www.pcsmi.com Corporate Phone: (800) 377-7271 CONFIDENTIALITY NOTICE - The information contained in this transmittal is confidential. It is intended for the addressee(s) stated above. If you are not an addressee you should not disclose, copy, circulate or in any other way use the information contained in this transmission. Such unauthorized use may be unlawful. If you received this transmission in error, please reply to me immediately so that the error can be corrected promptly. -----Original Message----- From: MUTI, Jean-Christophe [mailto:Jean-Christophe.MUTI@xxxxxxxxxxxxxx] Sent: Monday, March 24, 2003 4:28 AM To: 'foxboro@xxxxxxxxxxxxx' Subject: [foxboro] Math question hi list, Fun question for you all : Let's imagine a tank which is filled by the top and drained by the bottom. I have a level indicator on the tank (LI0101) and a flowmeter on the drainage pipe (FI0101) and i add a accumulator on it FI0101_A. How can i calculate every 10 minutes, the inlet flow ? I need a mathematic formula of course. Thank you all, it 's important. JC MUTI SEPPIC FRANCE jean-christophe.muti@xxxxxxxxxxxxxx =20 =20 _______________________________________________________________________ This mailing list is neither sponsored nor endorsed by Invensys Process Systems (formerly The Foxboro Company). Use the info you obtain here at your own risks. Read http://www.thecassandraproject.org/disclaimer.html =20 foxboro mailing list: //www.freelists.org/list/foxboro to subscribe: = mailto:foxboro-request@xxxxxxxxxxxxx?subject=3Djoin to unsubscribe: = mailto:foxboro-request@xxxxxxxxxxxxx?subject=3Dleave =20 _______________________________________________________________________ This mailing list is neither sponsored nor endorsed by Invensys Process Systems (formerly The Foxboro Company). Use the info you obtain here at your own risks. Read http://www.thecassandraproject.org/disclaimer.html foxboro mailing list: //www.freelists.org/list/foxboro to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join to unsubscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave