Évaluations - 4, GPA: 4.3 ( )

Fabricant : Omega Taille : 1.25 mb Nom Fichier : M3540.pdf Langue d'enseignement:

So, a reading may be displayed, for example, in units of weight or velocity instead of in amperes and volts. The controller determines scale and offset values based on two user-provided input values entered with the corresponding readings. There are two methods to scale this meter to display readings in engineering units. The first method is to scale with known loads. Do this by applying known loads to a transducer connected to a meter, or by simulating the output of the transducer with voltage or current simulator. The second method is to scale without known inputs. Do this by calculating input values based on transducer specifications and manually entering them through the front panel push-buttons. Example 1: Scaling with Known Loads (On-Line Calibration). When entering the input or reading values, disregard the position of the decimal point. If ENBL Enabled Load Submenu was selected, instrument is ready for scaling with Known Loads method. Apply a known load equal to approximately 0% of the transducer range. Press d 17) Press d at the IN.RD prompt. Display shows IN!2 Input 1 Submenu. Press d 18) Display shows the actual signal being received. Press d 19) Display advances to RD!1 Reading 1 Submenu. Press d 20) Display shows last stored Reading 1 value with 1st digit flashing. Press b & c 21) Use b and c buttons to enter RD!1 value. This value corresponds to Input 1 in terms of some meaningful engineering units. To show Input 1 as zero percent enter RD!1 value = 0000. Press d 22) Display shows IN!2 Input 2 Submenu. Apply a known load equal to approximately 100% of the transducer range. Press d 23) Display shows the actual signal being received. Press d 24) Display advances to RD!2 Reading 2 Submenu. Press d 25) Display shows last stored Reading 1 value with 1st digit flashing. Press b & c 26) Use b and c buttons to enter RD!2 value. This value corresponds to Input 2 in terms of some meaningful engineering units. To show Input 2 as 100% enter RD!2 value = 0100. This scaling method based on 2 input values entered with 2 corresponding reading. Up to 10 linearization points can be selected to customize the transducer curve. To select linearization points see “L.PNt” Submenu. 22 Max scale should not be more than 50% FS because of noise related issues. Press d 27) Display flashes STRD stored message momentarily and then advances to ALR1 only, if a change was made, otherwise advances to ALR1 Alarm 1 Menu. Example 2: Scaling without Known Loads. If DSBL Disabled Load Submenu was selected, instrument is ready for scaling Without Known Loads method. To scale without known inputs, calculate inputs based on transducer specifications and manually enter them on the via front panel push-buttons. The following example assumes load cells with this specification: Maximum Load: 100.0 lb Output: 3.0 mV/V Sensor Excitation 10 V Maximum Sensor Output = 3.0 (mV/V) x 10 (V) = 30 mV 1. Determine the correct values for Inputs (IN!1 and IN!2). Calculate IN!1 and IN!2 using the following equation: IN = (Sensor Output) x (Converison Number) x (Multiplier) Conversion number is a coefficient of conversion between input values and real full display range (10000 counts). See Table 3.1 below for proper conversion number. Table 3.2 Conversion Table INPUT RANGE CONVERSION NUMBER 0 ~ 100 mV 10000 / (100 x 1) = 100 cts/mV 0 ~ 1 V 10000 / (1000 x 1) = 10 cts/mV 0 ~ 10 V 10000 / (1000 x 10) = 1 cts/mV 0 ~ 20 mA 10000 / (20 x 1) = 500 cts/mV Multiplier determined by the Input Resolution setting (RESO in the INPT Menu). See Table 3.2 below for proper multiplier. Table 3.3 Input Resolution Multiplier INPUT RANGSOLUTIONERELOW HIGH 0 ~ 100 mV 1.0 10.0 0 ~ 1 V 1.0 10.0 0 ~ 10 V 1.0 10.0 0 ~ 20 mA 1.0 10.0 23 Determine IN!1 and IN!2 Input Range and Resolution. For our transducer select 0 ~ 100 mV range and LOW resolution (10 .V) IN!1 = 0 (mV) X 100 (cts/mV) x 1.0 = 0 IN!2 = 30 (mV) X 100 (cts/mV) x 1.0 = 3000 2. Determine correct values for Display Reading (RD!1 and RD!2). In most cases, RD!1 and RD!2 are equal to the minimum and the maximum of the transducer output range. RD!1 = 0000 RD!2 = 100.0 3. Scaling the controller. Press d 28) Press d at the IN.RD prompt. Display shows IN!1 Input 1 Submenu. Press d 29) Display shows last stored Input 1 value with 1st digit flashing. Press b & c 30) Use b and c buttons to enter IN!1 value (0000). Press d 31) Display advances to RD!1 only, if a change was made, otherwise press a to advance to RD!1 Reading 1 Submenu. Press d 32) Display shows last stored Reading 1 value with 1st digit flashing. Press b & c 33) Use b and c buttons to enter RD!1 value (0000). Press d 34) Display IN!2 Input 2 Submenu. Press d 35) Display shows last stored Input 2 value with 1st digit flashing. Press b & c 36) Use b and c buttons to enter IN!2 value (3000). Press d 37) Display advances to RD!2 only, if a change was made, otherwise press a to advance to RD!2 Reading 2 Submenu. Press d 38) Display shows last stored Reading 2 value with...

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