4830A Accelerometer simulator Instruction manual. IM4830A, Revision E1

Transcription

1 4830A Accelerometer simulator Instruction manual IM4830A, Revision E1

2 IM4830, Page 2

3 The ENDEVCO Model 4830A is a battery operated instrument that is used to electronically simulate a variety of outputs from vibration transducers. Also provided is a tachometer output that provides a TTL level output signal. The output signals can be set-up in actual pc or millvolts. All parameters are entered via a front panel key pad that is sealed per IP65. The following simulated sensor outputs are available from the Portable Simulator: Acceleration Displacement Velocity Tachometer Output signals are provided that simulate voltage mode accelerometers (IEPE, ISOTRON, etc) and charge mode accelerometers, both single-ended and differential types. While the 4830A provides an accurate and repeatable signal, it is not a substitute for the manufactures recommended calibration intervals. All units are provided with a padded carrying case, charger, snap-on filter for the battery charger and a twinax BNC connector. Optional cables are available from Meggitt Sensing Systems. Please contact the factory or your local representative/reseller for further information. This manual covers the basic operation on the 4830A along with a section on servicing and calibration. IM4830, Page 3

4 1. POWER/CHARGE CONDITIONS Power is provided by an internally mounted NI-CAD battery pack, which can be charged by applying a regulated 9V D.C. source to the DC input connector. The 9V source will also provide all the power required by the unit, reverting to battery power when the source is removed The internal battery charger will complete a full charge within 4 hours, the battery management system detects battery and ambient under/over temperature, cell voltage, fast charge time and reverts to trickle charge when limits have been reached. There are two LED's provided to indicate current status, power/trickle 'Charge and Fast Charge'. To charge the 4830A switch the power switch on the unit to 1, connect the power supply and switch it on. The red fast charge and orange trickle charge LEDs should both be lit. Once the unit is fully charged in the red, fast charge LED will extinguish. The orange trickle charge LED will remain lit indicating that the battery voltage is being maintained / topped up by a trickle charge current. This configuration is recommended for optimum charging of the unit. A power low warning shown on the bottom line of the display and can be cleared by taking the cursor position into the mode area i.e.: Hertz, but the message will be re-displayed in approximately 1 minute. Failure to charge will result in the unit powering down (display will blank) while retaining the units last settings. 2. POWER MANAGEMENT The unit will enter its 'Power Save' mode after approximately 5 minutes from the last keyboard action. This can be disabled by depressing the left and right keys together, a message will be displayed 'Auto-power down' and on releasing the keys a '*' symbol can be seen in the right-hand bottom corner indicating the auto power down function is disabled. NOTE: In this mode a significant reduction in battery operation times can be experienced, do not leave unit on when not in use. To enable 'Auto-Power shutdown' depress the left and right keys again on release the '*' symbol will be removed, auto-power mode is now enabled. IM4830, Page 4

5 In power save mode the systems power supplies are shutdown inhibiting any signal output, power to the display is maintained. Auto power save mode will be reset by the next key press (display will blink and software issue text will be displayed). 3. PARAMETER SETTINGS Parameter selection setting is achieved using the four keys left, right, up and down, the display is divided into two separate areas, on right hand side of the display is the 'mode' area, using the up and down keys to scroll through the various available modes. The second line down is used for editing the values of each parameter. Select which mode parameter to be edited by scrolling display until it appears on the second line down. Using the left-hand key move the cursor until it is over the digit that is to be modified, use 'up' to increase value, or down to decrease value, note that the values either side will change when roll-over occurs depending on count up or down. The cursor has to be returned to right-hand area to select a new parameter. The signal outputs will update immediately to reflect the new value. 4. MEMORY RESET To perform a 'Memory reset' depress the left and down keys simultaneously. On release a 'MEMORY RESET' message will be displayed, following a reset the factory default settings will be loaded into the units memory. 5. POWER SUPPLY The EHM1882 Power Supply and EHM1905 Ferrite Snap-On Cable Filter need to be assembled prior to use. This is necessary so the 4830A meets specifications. 1. Remove power supply wrapping and extend the cord. 2. Remove the ferrite filters wrapping. 3. Open the ferrite filter by gently lifting on the two plastic latches. 4. Open the power supply s cord starting about 1 inch from the end that plugs into the 4830A and run it through the trough in the open filter as shown in Figure Keeping the cord from being pinched, close the ferrite filter until the plastic latch snaps shut. IM4830, Page 5

6 Figure 1: Install snap-on ferrite Figure 2: Plug in power 6 PANEL DESCRIPTION AND ORENTATION Please follow the step by step instructions for set up and operation of the instrument. Refer to figure three for location on the output signal conditioners. The connectors provide the following outputs: TACHO: ICP: SE: mv: DIFF: Provides a simulated tachometer signal with TTL (5 Volt) pulses Provides a millivolt output signal as selected on the panel. This output includes current sinking to simulate IEPE (ISOTRON, ICP etc) accelerometers. A charge signal is provided to simulate charge-mode piezoelectric accelerometers. An output in millivolts may be selected with no current sinking. A Twin-BNC connector provides a differential charge to simulate differential chargeaccelerometers. IM4830, Page 6

7 The rear panel contains the power switch and charger input. The LED s labeled F and C indicate fast charge (F) and trickle charge (C). The charge mode is selected automatically based on the charge level of the internal battery. IM4830, Page 7

8 IM4830, Page 8

9 IM4830, Page 9

10 IM4830, Page 10

11 7. BATTERY REPLACEMENT In the event the battery requires replacement, it can be replaced with an Endevco model EBT26. It can be installed by Endevco or the user can replace the battery. The battery is located in the upper right corner in figure 3. Below are step-by-step instructions to follow for replacing the battery: 1. Remove the four screws on the bottom of the instrument. These screws may be located under the rubber feet. 2. Gently remove the top cover and the battery will be visible (see figure 3). The battery will lift out since it is held in-place when compressed by the upper and lower case. 3. It is recommended that the wires be cut close to the battery leaving the other end of the wires attached to the circuit board and plug. Strip the ends of the wire 4. Strip the ends of the leads on the new battery. 5. Solder the new battery leads to the leads that were left in the simulator. Cover the solder joint with shrink tubing 6. Reassemble the case and check for proper operation. 8 CALIBRATION AND TESTING Annual calibration is recommended to ensure accuracy and proper performance. Calibration service is available from the factory, or the user can perform the calibration by following the following procedures. 8.1 Test Equipment Unless otherwise stated, the following equipment is required. Items may be substituted with equipment of similar performance. 8.2 Testing DC Power Supply, 9 Volts regulated. The power supply provided with the 4830A is preferred Oscilloscope Frequency counter RMS Voltmeter Isotron Signal Conditioner model 4416B Single/differential charge amplifier model 6634C With the unit switched on, verify that the Battery Low message is not displayed. Use the 9 V regulated power supply to recharge the batteries, if required. The procedure may be performed with the power supply connected Turn the unit off and connect the 9 Volt power supply (note that the center pin is +). The unit should automatically turn on with the power supply connected and charging the internal batteries. Verify that the yellow LED charge indicator is lit when the power supply is connected. IM4830, Page 11

12 8.2.3 Depress the two left hand keyboard switches simultaneously to re-initialize the unit. Confirm the default settings: Frequency = 100 Hz, Sensitivity = 10.0 and g = Frequency Accuracy Connect the frequency counter to the mv output BNC connector. Set the 4830A sensitivity to 10.0 and the g level to Measure and record the actual frequency output for the following displayed frequencies: 1.0, 10.0, 100.0, , and 10,000 Hz. Limits: ±1% Measure and record the actual frequency output for the following frequencies: 111, 222, 333, 444, 555, 666, 777, 888, and 999 Hz. Limits: ±1% Connect the frequency counter to the TACH output socket. Set the 4830A frequency to Hz. Measure and record the output frequency for the following Ratio settings; 1.0, 10.0 and Limits are ± 1%. Verify Tach Output is 5 Volts peak to peak 8.4 Amplitude Accuracy (mv OUTPUT) Connect a true RMS voltmeter and an oscilloscope to the mv output socket. Set the 4830A frequency to Hz and the sensitivity to Measure and record the mv output for the following g levels; limits ± 1%. g Level mv Output Limits mvrms mvrms mvrms Note: Levels < 100 mv pk (70.7 mv Rms) will be affected by noise If the measurement results exceed the prescribed limits (see above table), re-adjust the unit using the following method. Set conditions as per paragraph and with the g level set for Adjust RV1 on the analog output board (see fig 3 for the location of the potentiometer) ) to obtain mvrms at the mv output socket Re-adjust the 4830A sensitivity to 1.0. Measure and record the mv output for the following g levels; limits ± 1%. g Level mv Output Limits IM4830, Page 12

13 , IM4830, Page 13

14 Figure 3 showing the interior of the 8530A with the cover removed. RV1 is located behind the vertical PC board. DO NOT ATTEMPT TO ADJUST THE THREE POTENTIOMETERS ON THE HORIZONTAL BOARD. The battery is located on the right side (large blue item). The battery will lift out and is held in-place by compression when the cover is replaced. 8.5 Amplitude Accuracy (IEPE, ISOTRON, ICP Output) With the exception of the Tach, all other outputs of the 4830A are derived from the mv output. To verify their operation, suitable calibrated signal conditioners should be used, e.g. for the IEPE (Isotron) an Endevco 4416B, for an S.E. -and differential change, A Meggitt (Endevco) Model 6634C Connect the True RMS Voltmeter and Oscilloscope to the output of the Isotron Signal Conditioner Connect the True RMS Voltmeter and Oscilloscope to the output of the Signal Conditioner and Verify the Status LED is lit. Set the signal conditioning gain to X1 and the 4830A sensitivity to 10. Measure and record the 4416B for the following g settings. The limits are ±1.5%. IM4830, Page 14

15 g Level mv Output Limits mvrms mvrms mvrms Amplitude Accuracy (S.E. Charge Output) Connect the S.E. Charge Output to the input of the Model 6634B Signal Conditioner. Set the 6634B for: Type = SEPE, Sens = 10.00, FS = 20.0, Mode = g, DC = pk and Filter = Out. Set the 4830 for a frequency of Hz, Sens= 10.0 and g = Record the displayed g level on the 6634B. Limits 9.8 to Re-adjust the 4830A for g = 100 and adjust the 6634B FS to 200. Record the displayed g level. Limits 98 to Re-adjust the 4830A for g = 1 and adjust the 6634B FS to Record the displayed g level. Limits 0.98 to Amplitude Accuracy (DIFF Charge Output) Connect the DIFF. Charge Output to the input of the Model 6634B Signal Conditioner. Set the 6634B for: Type = DIFF, Sens = 10.00, FS = 20.0, Mode = g, DC = pk and Filter = Out. Set the 4830 for a frequency of Hz, Sens= 10.0 and g = Record the displayed g level on the 6634B. Limits 9.8 to Re-adjust the 4830A for g = 100 and adjust the 6634B FS to 200. Record the displayed g level. Limits 98 to Re-adjust the 4830A for g = 1 and adjust the 6634B FS to Record the displayed g level. Limits 0.98 to A, V, and D (Acceleration, Velocity and Displacement) Set the 4830A frequency to 61.4 Hz, Sens = 10.0 and g = Verify that the following is displayed: ms^2 = and ips = Re-adjust the frequency to Hz. Verify the following display: mils = Re-adjust the frequency to Hz. Verify the following display: mm = (fro Rev D4 firmware verify display reads: Tm = ). IM4830, Page 15

16 8.8.4 Re-adjust the frequency to Hz. Verify the following display: m/s = (For rev D4 firmware verify that the display reads mm/s = TROUBBLE SHOOTING GUIDE a) Corrupted Display: If the display is corrupted (Due to low battery or transient power glitches). The problem can generally be corrected by doing a Memory Reset as described in item 4. If the problem persists, the unit is most likely defective TECNICAL SUPPORT For technical assistance, contact the applications engineering department at Meggitt Sensing Systems or your local representative or international distributor. Questions If you have any questions regarding the use of this or any Endevco product, please contact Endevco Application Engineering at in North America, or your local sales representative. IM4830, Page 16