Thickness Gauge for Plastic Foil VDM E/Su Operating Instructions VDM-E5 erstellt am 30.4.97 geprüft am: freigegeben am Bemerkungen Rev.02 Seiten:8 Name: Rietdorf Name: Name:
measuring ++ controlling ++ recording ++ automation ++ documentation Table of Content G G Safety Precautions, please read carefully!... 3 Intended use of this machine... 3 Design and function... 4 Zero setting... 6 Measurement... 6 Maintenance... 7 2 VDM E/Su Operating Instructions VDM-E5
FRIEDRICH VOLLMER Feinmeßgerätebau GMBH, D-58093 Hagen, Verbandsstraße 60, ) +49 2334/507-0, Fax +49 2334/53015 Safety Precautions, please read carefully! This manual has to be handed to the machine operator, and one copy must be permanently available to operator and service personnel. Nobody is allowed to work on or with this gauge, before he has read and understood this manual. Feel free to call the Vollmer company in case of any questions (phone +49 2334 507 0). Warning, hazard of electric shock. Never open the electronic cabinet as long as the power cable is plugged in. There are no user serviceable parts inside the cabinet. Call for qualified service personnel to open the electronic cabinet in case of trouble. Do the same if you want to change the drive speed (potentiometer inside the cabinet). Secure long hair and loose clothing before operating the gauge. When the drive speed and power remain unchanged after the factory settings, the drive stops before causing damage when fingers are caught in the gap. Intended use of this machine This gauge must be used exclusively for the measurement of plastic film. It must be firmly installed in its intended position and electrically and electronically connected as intended by the Vollmer company. Any alteration might cause severe personal injury or material damage. VDM-E5 Operating Instructions VDM E/Su 3
measuring ++ controlling ++ recording ++ automation ++ documentation Design and function The Vollmer VDM foil thickness gauge measures samples of strong foil as well as of very thin foil down to a thickness of 10 microns. The measurement result is indicated on a measurement amplifier and it is available for statistical data evaluation. Digital measurement data which is continuously put out during a measurement are sent to the computer via a bus system. The VDM gauge is most suitable for process supervision on extrusion units. A specially designed drive unit pulls the foil samples through the gap between two LVDT measurement transducers. The drive unit consists of two sets of rollers, which are pulling two sets of belts. One set of belts drives the foil sample from the bottom side, while the other holds down the sample from the top side. Due to this construction the VDM gauge can measure even very thin foil without crumpling. The gauge operates with two measurement transducers with easy movable rams. They measure the passing foil simultaneously from the top and from the bottom. Due to foil thickness changes the transducer tips are pushed apart or come closer. The transducer tips have crowned hard metal surfaces, which provide a safe contact to the surface without deforming the foil. At its rear side each transducer has got a differential transformer. The transducer ram is connecting the movable core of this transformer to the measurement tip which is sliding on the foil surface. In this way any movement of the measurement tip is measured inductively. All changes within both transducers are passed to a VMF measurement amplifier, where they are added (sum measurement). The VMF amplifier indicates a measurement result as deviation from zero, i.e. the difference to the preset nominal size. Nominal size in 0.0001 inch is adjusted with a thumb wheel switch. After setting of a nominal size, the measurement signal is electronically converted by the decade switch signal, in such a way that the amplifier will indicate 0 when the gauge is measuring the selected nominal size. 4 VDM E/Su Operating Instructions VDM-E5
FRIEDRICH VOLLMER Feinmeßgerätebau GMBH, D-58093 Hagen, Verbandsstraße 60, ) +49 2334/507-0, Fax +49 2334/53015 VDM foil thickness gauge: Two motor driven rollers (right and left below the sample) pull the foil sample trough the gauge by means of two belts. Another set of rollers with two belts is holding down the sample. Between the belt tracks two inductive measurement transducers measure the foil thickness. VDM-E5 Operating Instructions VDM E/Su 5
measuring ++ controlling ++ recording ++ automation ++ documentation Zero setting For zero setting, the guide rollers and the transducer tips are closed while the gauge is set to nominal size zero. Then the amplifier is set to zero. After that, the gauge is ready for measurement. Run this simple procedure whenever the indication of the empty gauge is not exactly zero. The following shows a calibration step by step: - main power on - set nominal size to zero (thumb wheel switch) - push the 'read in nominal size' button to read the zero value into the VMF amplifier - close measurement transducers (black ball lever on the gauge head) - set the VMF amplifier to zero by means of the 'Master' function Note Transducer symmetry should be checked regularly (see extra manual). Measurement Select nominal size before starting a measurement. Then insert a foil sample between the rollers and start the measurement. The drive unit pulls the sample through the gauge at an even speed. After the VDM gauge was turned on, the unit should be set to zero and checked for transducer symmetry adjustment (see separate manual). The following shows a measurement step by step: - set the 5-digit thumb wheel switch to nominal size (the right hand digit is 0.0001", i.e. one tenthousandth of an inch). - select resolution on VMF indicator - push the 'read in nominal size' button to read the new nominal size into the VMF amplifier - push the black ball lever to the right (this lowers the rollers and starts the drive unit) - insert the foil sample from the left towards the right During measurement the VMF amplifier indicates the deviation of the measured foil thickness from the nominal size. Additionally, the measurement signal is available for a recorder or for evaluation by PC. 6 VDM E/Su Operating Instructions VDM-E5
FRIEDRICH VOLLMER Feinmeßgerätebau GMBH, D-58093 Hagen, Verbandsstraße 60, ) +49 2334/507-0, Fax +49 2334/53015 Maintenance The VDM gauge does not need much maintenance. Only the transducers should be checked regularly for easy motion of the transducer ram and for clean measurement tips. If the transducer rams are not easy movable, or if dirt builds up on the measurement tips, the transducers need to be cleaned or serviced. Transducer servicing is described in an extra manual. VDM-E5 Operating Instructions VDM E/Su 7
measuring ++ controlling ++ recording ++ automation ++ documentation A transducer can be removed from the gauge after the clamp screw in the measurement frame was loosened. Please do carefully support the measurement frame during this procedure, in order not to change its position. The gauge can produce correct measurement results only, when the transducers in the measurement frame stand exactly perpendicular on the foil surface. The bottom transducer can be removed after the aluminium side panel on the right hand was taken off. For transducer reinstallation connect only the bottom transducer to the VMF amplifier. The put an even metal sheet on top of the lower set of belts. Insert the bottom transducer into its hole in the measurement frame and push it against the metal sheet. Clamp it not too hard when the amplifier indicates +0.01" or 250µm (amplifier should be switched to the 0.03" or 1000µm measurement range). Now remove the metal sheet and additionally connect the upper transducer to the VMF. Insert it into the measurement frame and push it down against the bottom transducer until the VMF indicates zero. Then switch the VMF to the 0.0003" or 10µm measurement range and clamp the transducer in a position close to zero. Eliminate minor deviations from zero by means of the VMF 'Master' function. Note Do not clamp the transducers too hard. This might deform the transducer housing and the transducer ram might get too much friction. 8 VDM E/Su Operating Instructions VDM-E5