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DIGITAL PRESSURE CONTROLLER MODEL 7252 MODEL 7252 USER’S MANUAL RUSKA INSTRUMENT CORPORATION 10311 WESTPARK DR., HOUSTON, TEXAS 77042 (713) 975-0547 FAX: (713) 975-6338 e-mail: ruska@ruska.com http://www.Ruska.com Release: 7252-1D01 Revision: A Date: 09/16/03...
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WARRANTY Ruska Instrument Corporation warrants its products to conform to or exceed the specifications as set forth in its catalogs in use at the time of sale and reserves the right, at its own discretion, without notice and without making similar changes in articles previously manufactured, to make changes in materials, designs, finish, or specifications.
SAFETY SUMMARY The following are general safety precautions that are not related to any specific procedures and do not appear elsewhere in this publication. These are recommended precautions that personnel must understand and apply during equipment operation and maintenance to ensure safety and health and protection of property. KEEP AWAY FROM LIVE CIRCUITS Operating personnel must at all times observe safety regulations.
TABLE OF CONTENTS WARRANTY ......................-ii- COPYRIGHT NOTICE .................... -iii- REVISION NOTICE ....................-iv- REVISION HISTORY....................-v- CHANGE LANGUAGE................... -vi- SAFETY SUMMARY ....................-vii- TABLE OF CONTENTS ..................-viii- SECTION 1.0: GENERAL INFORMATION INTRODUCTION................1-1 GENERAL INFORMATION ..............1-1 FEATURES ..................1-1 STANDARD EQUIPMENT & OPTIONS ..........1-3 SECTION 2.0: THEORY OF OPERATION INTRODUCTION................2-1 POWER SUPPLY.................2-2...
It is also used to monitor barometric pressures, vacuum systems, and differential pressure devices. The 7252 has two full scale pressure ranges and two pressure controllers integrated into one instrument. FEATURES The following features are available on all Model 7252 DPC’s.
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how close the actual pressure is to the commanded pressure, as well as how close the commanded pressure is to the DPC’s full scale pressure. Friendly Display: The DPC’s color active matrix TFT display combines a bright, low- glare readout with a wide viewing angle. During normal operation, the measured pressure is easily visible from a distance of 10 feet (3 meters).
Table 1-1. To order these items, please contact Ruska Instrument Sales in the U.S. at (713) 975-0547. TABLE 1-1 OPTIONS LIST FOR THE MODEL 7252 DPC Option Ruska Instrument Corp. Part Number (RIC #) LabView Driver (National Instruments)
This section of the manual describes the DPC’s component modules (Figure 2–1) and provides a general discussion of each. The 7252 has two pneumatic control and two primary transducer modules. Primary Transducer Module 2...
The DPC’s universal power supply accepts AC voltages from 90 to 260 volts at 47-63 Hz. and DC voltages from 100 to 370 volts. This quad–output supply produces +5 VDC, +/-12 VDC, and 24 VDC which are distributed to the Control and Backplane Boards. ELECTRONICS MODULE 2.3.1 BACK-PLANE BOARD...
TABLE 2–1 CONVERSION FACTORS Unless specified otherwise, conversion factors are based on ANSI 268–1982. Symbol Description Conversion Factor InHg inches of mercury (0 °C) = kPa x 0.2952998 InHg inches of mercury (60 °F) = kPa x 0.296134 KiloPascals = kPa x 1.0 Bars = kPa x 0.01 pounds per square inch...
Control Section PRIMARY SENSOR VACUUM SENSOR Option FIGURE 2–2A MODEL 7252 DPC GAUGE PNEUMATICS DIAGRAM 0.36 to 2500 psig (2.5 kPa to 17.2 MPa) Full Scale Ranges Note, this diagram depicts only one of the two 7252 channels. THEORY OF OPERATION...
INNER LOOP CONTROL SENSOR Control Section PRIMARY SENSOR VACUUM SENSOR Option FIGURE 2–2B MODEL 7252 DPC ABSOLUTE PNEUMATICS DIAGRAM TO 50 PSIA (340 kPa) FS Note, this diagram depicts only one of the two 7252 channels. Valve Measure Mode Vent Control Mode Zeroing...
Gauge mode DPC to function in a Absolute system. A 7252 must have a minimum full scale pressure range of 14.7 psig (101 kPa) in order to be configured to operate in the simulated absolute mode using the barometric reference sensor.
Module. Please refer to Appendix A for gas specifications and supply pressure limits. On the 7252, there are two supply pressure ports, one for each channel. A separate regulated pressure supply will need to be connected to each individual supply pressure ports.
2.4.2.3 Pressure Control Pressure control is performed by a dual-loop control system. The inner loop is a digital loop using a high frequency response silicon strain gauge sensor, a digital controller, and two pulse-width modulated solenoids. The two solenoids either add gas to the test port or remove it.
2.5.5 PID CONTROL The outer loop pressure controller is a form of PID control executed every 100 milliseconds (10 times per second). The pressure is controlled to an exponential decay curve. ∫ − − − A dt d S = Set-point A = Actual V = Control Output p,i,d = Control Coefficients...
TRANSDUCER MODULE 2.6.1 QUARTZ BOURDON TUBE SENSOR (TRANSDUCER01) The quartz Bourdon tube sensor is mounted in a machined aluminum housing. The sensor consists of a helical quartz tube with a mirror affixed to one end, as shown in Figure 2-5. A rigid beam is attached transverse to the axis of the helical tube.
FIGURE 2–6 PHOTOCELL/LIGHT SPOT 2.6.2 SENSOR BOARD A temperature sensor and the quartz Bourdon tube pressure sensor are monitored by the Sensor Board. The Sensor board is also used to control and maintain the sensor housing at 50°C. 2.6.3 LINEARIZATION TERM As described in the previous section, the relationship between the pressure being measured and the current required to keep the quartz Bourdon tube in its zero position is the main principle behind the operation of the DPC’s sensing element.
2.6.4 AUXILIARY SENSORS Auxiliary sensors are sensors such as the oven temperature sensor. These are reference sensors aligned at the factory and are utilized by the firmware. 2.6.4.1 Case Reference Vacuum Sensor - Option A case reference vacuum sensor is a user selectable option. This option includes a vacuum sensor installed into the test port on absolute units and the sensor case reference port on differential units and can be read directly by the DPC.
viewing the MENU | DISPLAY screen and verifying that the temperature is at 50 C. In addition to the temperature, this screen will show the duty cycle of the oven. When operating the system in either a very cold or hot environment, if the oven in unable to maintain the temperature of the internal oven, the DPC will generate an Oven Control Failure error messages.
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The following equations are used by the control algorithm to adjust and correct the pressure signal. Zero Coefficients Zero correction for High FSR (Full-Scale Resistors) Value is in counts (7,381,975 = full scale of current sensor). Zero correction for Low FSR. Value is in counts (7,381,975 = full scale of low FSR) Hardware zero correction.
SECTION 3.0 INSTALLATION INTRODUCTION This section of the manual discusses initial installation for the Model 7252 DPC. Installing the DPC involves connecting the supply and test pressure tubing, powering up the unit, and configuring the system through the front panel.
Warning – Make sure that you connect the proper pressure supply to the correct pressure channel. The pressure range for each channel is identified on the front panel of the 7252. This is depicted using the letter A and B for the two channels and the pressure INSTALLATION...
15 feet (5 meters) when minimum diameter tubing is used. 3.5.3.1 SINGLE TEST PORT OPERATION - OPTION Some versions of the 7252 allow the instrument to be set-up where the test port of both controllers are connected together. A flag must be set in the [MODE] MENU|Setup|User menu to allow the system to operate in this mode.
the lower pressure channel from the higher pressure channel when controlling pressures that are greater than the full scale range of the low pressure channel. This option is only available with instruments where both channels have a full scale pressure range that is greater than 10 psi (69 kPa) and less than or equal to 1000 psi (6.9 Mpa).
SEE U S ER 'S M A N U A L TO TU R N O N . FIGURE 3-1 MODEL 7252 BACK PANEL 3.5.5 VACUUM TRANSDUCER INSTALLATION On permanent absolute models of the DPC’s (15–50 psia), a vacuum sensor is required to zero the instrument.
10. Replace the DPC’s cover, plug the power cord back into the DPC, and turn the power on. 3.5.6 VACUUM SENSOR OPTION The DPC is also available with a vacuum sensor option. On a permanent absolute instrument, this sensor is used to zero the Ruska quartz sensor at a high vacuum. On a DPC that has the Evacuated Reference Option, this vacuum sensor is used to monitor the vacuum level in the reference port when the reference port is pulled to a hard vacuum allowing the DPC to operate in the absolute mode.
A: 1000 psi B: 10 psi FIGURE 4-1 MODEL 7252 FRONT PANEL Numeric Keypad: This includes the number keys, the decimal point [.], and the change sign key [-]. The [UNITS] key changes between units of measure, [MODE] held down for 5 seconds changes the language.
Enter Menu State Menu Enter Setup Menu Setup Set high, low & slew limits, control mode, control band and Limits access code Set step size, head correction, filter and display digits User Define user-defined units of measure Units Set baud, parity, data bits, stop bits, GPIB address Remote Set date and time, reset machine, view software version System...
The [F3] key places the unit in Vent mode. This opens the test port to atmosphere and rapidly reduces the pressure, [ENTER] is required to confirm the operation. The [F5] key places the unit either the stop or the jog mode and the rotary knob is then used to set the control set-point by the correct step or jog amount.
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CHANNEL A: MAIN MENU This is the channel A Main Menu. The double sized numbers in the top center of the display shows the current measured pressure (0.00 psi diff). The upper left corner shows the current mode of the DPC (MEASURE, CONTROL or VENT). The right side of the screen shows a bar graph displaying the current pressure relative to a user-configurable full-scale value.
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Step 3. When the unit desired is highlighted, press the [ENTER] key on the far right side of the front panel, under the numeric keypad. The display will return to the MAIN screen with the current units. The second part of this tutorial uses the DPC to generate pressure. The pressure supply must be connected and the test port must be connected to a closed volume, in accordance with Section 3.5 of this manual.
4.1.1 SELECTING LANGUAGE The 7252 DPC can operate in a variety of different languages. To select a different language, press and hold the [MODE] key for 5 seconds. The current language will be highlighted. Use the rotary knob to highlight a new language and hit the [ENTER] key to select that language.
Absolute). The Main Menu can always be reached by repeatedly pressing [PREVIOUS]. The model 7252 is designed such that all of the commonly used functions are accessible by a direct key on the key pad or from a top level function key. Less commonly used set- up type functions are accessible through the menu function key.
This function is not available on permanent absolute versions of the 7252. STEP/JOG This feature is only available when operating in the single channel mode. In addition to entering the pressure set-point through the key-pad, the pressure set-point can be changed using either the step or the jog functions.
pressure step is user defined. The Jog function is most often used when calibrating mechanical gauges such as a dial gauge and the operator wishes to change the pressure until the mechanical gauge indicates a cardinal point. The operator can then read the higher resolution DPC to determine the actual pressure value when the mechanical gauge is indicating a cardinal point.
Setup is used to configure the system. It includes setting all of the limits, user parameters, user-defined units of measure, remote interface and system setup. On the 7252, the User and Limits screens are separate for each channel and must be set up independently.
4.6.1.1.4 Control Band – There are two common pressure control approaches that are available with the Ruska 7252 DPC. One of the most common control styles is an Active controller where the controller remains operative and holds the pressure at a commanded set-point.
any added uncertainty in the measurement system due to the controller since the controller is Passive during the high accuracy pressure measurements. As an example, if a 100 psi (690 kPa) full scale DPC was set-up with the Control Off Band at 0.001 psi (0.007 kPa) and the Control On Band set to 0.005 psi (0.035 kPa).
CHANNEL A: Menu | Setup | User - Menu 4.6.1.2.1 Step Size - In addition to entering the pressure set-point by the key-pad, the pressure set-point can be changed using the step function. The step function is used primarily when the operator is taking pressure steps in equal pressure increments. The size of the pressure step is user defined.
6. Press Position [F4] to select if the position of the Device Under Test is either “Above” or “Below” the 7252. The selected units will be highlighted and appear in the Gas Head description. 7. Use the rotary knob to highlight the label “Gas Head.”...
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thus the conversion factor simplifies to mTorr = kPa x 7500.6180 CHANNEL A: MENU | SETUP | UNITS - MENU 1. The pressure units are defined from the Units | Define | Menu. From the Main Menu (press [PREVIOUS] until the Main Menu appears) press Menu [F6], then Setup [F2], then Units [F3].
The options are Standard Communication for Programmable Instruments (SCPI) which is the only interface available for the 7252. 4.6.1.4.3 Serial Interface Set-Up – The operator can set-up the Baud Rate, Data Bits, Parity, and Stop Bits for the Serial Interface.
It does not require any external computer or software in order to perform a successful calibration. It also has the capability of being calibrated remotely through either the RS232 or IEEE-488 interface. The 7252 will guide the operator through a menu driven calibration procedure identifying the pressures that should be supplied by a standard.
Calibrate [F3]. 2. Press the Access [F4] key. If there is a password in the system other than 0, then you must enter the current valid password into the 7252 before it will allow you to modify the password. 3. Use the numeric keypad to enter the new calibration password.
The DPC can store up to 1,000 program steps that may be divided among a maximum of 20 named programs. The Program menu operates only on the current channel. The other channel will be in measure mode while the program is running. 4.6.3.1 Preparing to Program Before entering a test sequence, consider the items discussed below.
programmed individually since the starting set-point is 30 psi and the ending set-point is 20 psi. Detailed instructions for entering these items are given in the sections that follow. 4.6.3.2 Entering a New Program To program the DPC, use the keys on the front panel to change values on the DPC’s program editing screen.
5. Using the numeric keypad, enter the values for Pressure, Tolerance, Dwell time, and Max time, pressing [ENTER] after each value. The rotary knob may be used to skip fields. 6. At the 0 step, enter the next pressure and the DPC will automatically insert a new pressure step.
CHANNEL A: MENU | PROGRAM | EDIT | AUTO - MENU 6. Using the numeric keypad, enter the values for Start, Stop, Tolerance, Dwell time, Max time, number of pressure Points up, and number of pressure Points down, pressing [ENTER] after each value. The rotary knob may be used to skip fields.
CHANNEL A: MENU | PROGRAM | EDIT | NAME – MENU 5. Use the < [F4] and > [F5] keys to highlight a character. 6. Turn the rotary knob to select the character from the character set. 7. To correct a mistake, press Clear [F4] and return to step 5. 8.
show up in the scratch pad located at the bottom of the window. Press [Enter] to accept the edited value. 5. To add a step to the program, first move to the step after the new step. For example, to insert a step between steps 3 and 4, move to step 4. Press Insert [F4].
4.6.4 MENU | TEST The Menu | Test section of the system is used to perform a number of the diagnostic and tuning functions that are available with the 7252. The Sweep and Control test operate on the current selected channel.
CHANNEL A: MENU | TEST - MENU 4.6.4.1 Menu | Test – Sweep Test The sweep function can be used to automatically exercise the elastic sensing element of the device under test prior to performing a calibration. For the DPC to perform the sweep test, input the high and low set-point pressures, the pressure control tolerance, the dwell time at set-point, and the number of cycles to perform.
6. To stop the program, press Stop [F5]. The program will stop running but the DPC will continue controlling to the current set-point. 4.6.4.2 Menu | Test – Self Test The DPC can perform electrical and pneumatic self test to assist in trouble shooting potential problems.
CHANNEL A: MENU | TEST | SHOP1 – MENU 4.6.4.5 Menu | Test – Control The Menu | Test | Control menu of the system is used to tune the controller. On new instruments, the controller is tuned at the factory and therefore, the user should not need to access or make any adjustments to the controller using this menu.
SECTION 5.0 REMOTE OPERATION CAPABILITIES The DPC can be operated remotely by a computer. Two interfaces are supported: IEEE- 488 and RS-232. Both interfaces support SCPI (Standard Commands for Programmable Instruments). The IEEE-488 interface additionally supports emulation of a Ruska Single Channel Interface Panel (Models 6005-701 and 6005-761).
The RS-232 connection is a DB-9P connector found on the back panel of the DPC. It is located on the processor board. The following pins are used; all other pins are reserved. Pin # Direction Signal Receive Data Transmit Data ——...
4. Repeat steps 2 and 3 to set all parameters needed. DEVICE MESSAGES 5.4.1 SCPI COMMAND FORMAT SCPI mnemonics have two forms: long and short. The short form is all in capital letters. The long form is the entire mnemonic. Commands may use either the short form or the entire long form.
5.4.3 ANSI/IEEE 488.2-1987 COMMAND SUMMARY *CLS Clear Status *ESE? Event Status Enable Query *ESE <number> Event Status Enable *ESR? Event Status Register *IDN? Identification *OPC? Operation Complete Query (Returns 1) *OPC Operation Complete *RST Reset *SRE? Service Request Enable Query *SRE <number>...
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:TARE :VALUE <number> get/set tare value :STATe ON|OFF set tare state using current press. :LIMit :LOWer <number> low pressure limit :SLEW <number> slew rate limit :UPPer <number> high pressure limit :VENT <number> auto-vent limit CALibration :MODE? calibration edit enabled? :MODE <number> request calibration edit [:PRESsure]? A Pressure...
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Same as PRESsure2 above :VACuum? A Vacuum Same as PRESsure2 above :VACuum11? B Vacuum Same as PRESsure2 above :TEMPerature? A Gas Temperature Same as PRESsure2 above :TEMPerature2? A Sensor Temperature Same as PRESsure2 above :TEMPerature11? B Gas Temperature Same as PRESsure2 above :TEMPerature12? B Sensor Temperature Same as PRESsure2 above...
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:LOWer? returns low cal point :REFerence [:HEIGht] <number> gas head height :MEDium N2|AIR gas head medium :PRESSure11 [:RESolution] <number> sets pressure display resolution :AUTO ONCE returns to default resolution :MODE ABSolute|DIFFerential|GAUGE|TARE :RANGE [:UPPer]? full scale value in units (calibrated) :LOWer? returns low cal point :REFerence [:HEIGht] <number>...
:meas? MEAS? To set the control pressure setpoint to 50, all of the following commands are equivalent: SOURCE:PRESSURE:LEVEL:IMMEDIATE:AMPLITUDE 50 SOUR:PRES:LEV:IMM:AMPL 50.0 PRESSURE +50 PRES 50 To zero the unit via the remote interface use the following sequence: CAL:ZERO:INIT Enter Zero Mode CAL:ZERO:INIT? Read Status (Mode, Pressure, Temperature, Reference) and Wait Until Stable.
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Bit 5 EBS - Event status bit. Set when an event enabled in ESE occurs. Bit 4 MAV - Message available. Set when a response is ready to be sent. Bit 3 Questionable status summary. Set when an event enabled in QUES:ENABLE occurs. Bit 2 Error/event queue not empty.
SERIAL OPERATION The RS-232 port accepts the same SCPI commands as the IEEE-488 port. commands can be terminated by a carriage return (hexadecimal 0D) or a line feed (hexadecimal 0A). The responses are always terminated by a carriage return followed by a line feed.
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{ printf ("GPIB Driver not installed.\n"); return; /*-----------------------------------------------------------*/ /* Initialize 7250 Interface UNIT %FS Set units to percent of full scale */ PRES 20.0 Set control setpoint to 20 %FS PRES:TOL 0.001 Set control tolerance to 0.001 %FS */ OUTP:MODE CONTROL Enter control mode /*-----------------------------------------------------------*/ write_7000 ("UNIT %FS;:PRES 20.0;TOL 0.001;:OUTP:MODE CONTROL\n");...
unsigned char status7; int retval; /*---------------------------------*/ /* Check for GPIB Interface Errors */ /*---------------------------------*/ if (ibsta & ERR) { printf ("GPIB Status=%4X Error=%d\n"); return 1; /*-----------------------*/ /* Check for 7250 Errors */ /*-----------------------*/ retval = 0; while (!kbhit ( )) { ibrsp (device, &status7);...
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double pressure; /* Pressure read from unit */ status; /* Status register from unit */ check_errors (void); zero (void); void write_7000 (char *s); void request_7000 (char *s); /*--------------------------------------------------------------------*/ void main (void) char *p; /*---------------------------*/ /* Initialize GPIB Interface */ /*---------------------------*/ device = ibdev (0, /* First GPIB Board */ /* GPIB Address of 7250 */...
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/*-------------------------------------------------*/ /* Wait for calibration values to be within limits */ CAL:ZERO:INIT? /*-------------------------------------------------*/ { if (kbhit ( )) { getch ( ); break; request_7000 ("CAL:ZERO:INIT?\n"); sscanf (buffer, "%d,%d,%d,%d", &cstat, &pstat, &tstat, &rstat); if (check_errors ( )) return 0; gotoxy (20, 5); if (pstat == 0) cprintf ("Stable ");...
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/*--------------------------------------------------------------------*/ /* check_errors : display all GPIB and 7250 error messages return TRUE if any errors were found /*--------------------------------------------------------------------*/ int check_errors (void) unsigned char status7; int retval; /*---------------------------------*/ /* Check for GPIB Interface Errors */ /*---------------------------------*/ if (ibsta & ERR) { cprintf ("GPIB Status=%4X Error=%d\r\n", ibsta, iberr);...
SECTION 6.0 MAINTENANCE INTRODUCTION Very little maintenance is required for the DPC. This section of the manual discusses suggested maintenance procedures. OBSERVING THE SOFTWARE VERSION NUMBER Follow the steps below to observe the DPC’s software version number. 1. If necessary, press [PREVIOUS] several times to return the display to the Main Menu.
TABLE 6-1 ELECTRONICS SELF TEST Test Action on failure RIC Part # Description Processor Tests the processor chip Replace processor board. 7215-586-3 Clock Tests the real time clock Replace processor board. 7215-586-3 Timer Tests the 10 ms interval timer Replace processor board. 7215-586-3 EEPROM Tests the nonvolatile memory...
open solenoid valves that are powered through the vacuum pump power switch. When the vacuum pump is turned on, the solenoid valve is energized and closes allowing the pump to operate normally. When the pump is turned off, power is removed from the solenoid and the vacuum is vented to atmosphere.
The sensors coefficients are then shown below the sensor label. On the 7252, there are two primary sensors. The first sensor that is shown is the primary measuring sensor A. This is indicated by the word A Primary displayed in the top of the display.
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7252. The number of pressure points required to calibrate the DPC will vary based on whether the DPC is a 7252 or 7252i and if it has a vacuum (negative gauge) option. The screen will display a table noting the following information;...
2.3 Using your calibration standard, generate the pressure shown in the Apply column. When the measured pressure stabilizes, use the DPC’s numeric keypad to enter the actual pressure applied by the calibration standard and then press ENTER. Do not enter the measured pressure reported by the DPC. If necessary, use the [CLEAR] key to correct a mistake in the edit field.
6.4.2 VACUUM (NEGATIVE GAUGE) CALIBRATIONS Vacuum mode is an available option. The following configuration should be used when calibrating in the Vacuum mode. FIGURE 6-4 VACUUM (Negative Gauge) CALIBRATION To calibrate in Vacuum mode with the configuration shown in Figure 6-4, the following actions should be taken.
2. Connect a pressure standard to the Reference Port of the DPC. Note, on the 7252, there are two reference ports. Typically the RPT is connected to the top reference port. However, this can vary based on the configuration of the 7252. If the barometric sensor does not react when changing the pressure in the top reference port, try the lower reference port.
Note, on the 7252 each sensor will have its own independent vacuum sensor. 3. If desired, change the DPC’s units of measure (see Section 4) to match those of the calibration standard.
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CAUTION: Never randomly adjust the calibration coefficients. Only qualified personnel with valid backup data should be allowed to edit the coefficients. If the backup coefficients are questionable, perform the calibration procedure in its entirety. 1. Verify that the DPC is in Measure mode (Section 4.0). 2.
6.4.6 ZEROING The zeroing procedure is performed to correct for system zero shift and does not require a full calibration. The most important requirement for performing a valid zeroing procedure is to guarantee that there is not a pressure differential between the sensor’s test port and case reference.
6. Press [PREVIOUS] to return to the Main Menu. 6.4.6.2 Absolute Instruments A vacuum pump must be connected to the reference port. A vacuum gauge should be installed for measuring the case reference pressure. This gauge should be installed as close to the sensor as possible. There is an 1/8-inch NPT fitting available for this installation inside the DPC near the sensor.
6.4.6.3 RPT - Simulated Absolute Instruments Simulated absolute DPC’s contain two sensors that require periodic zeroing. The primary sensor is zeroed according to the instructions in Section 6.4.5.1 or 6.4.5.2. barometric sensor is zeroed according to the following instructions. 1. Verify that the Reference Port is open to atmosphere. 2.
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Using the T-shaped Photocell Centering Tool (RIC # 7252-111), adjust the photocells by placing the tool in the hole in the back of the sensor and turning the tool slightly. The screen will show a number of horizontal lines.
same width that you observed it moving from tightening the Allen screw, and now offset it in the opposite direction by this same width. 11. Again, tighten the Allen screw. Now the width of the yellow line should be minimized. 12.
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Auto-tune. There are two options available to the operator. Full – This fully characterizes the control function of the 7252. It automatically adjust the control valve biases and aligns the inner loop high control pressure sensor to the high accuracy quartz sensor.
Auto-Tune should be run to characterize the new hardware. FAN OPERATION The fan in the 7252 can be turned on or off. It is recommended to keep the fan ON since this will extend the life of the power supply.
5. When the upgrade is finished, Update7 running on the PC and the 7XXX should both display Complete. 6.8.1 Model 7252 Controller Software Upgrade In addition to the main code, the 7252 include code for the pressure controller. The controller software version can be viewed by pressing the MENU/TEST/REMOTE/SERIAL2 MAINTENANCE...
Note, when updating the controller code, the 7252 will display various error messages. This is expected. The front display will freeze on the 7252 when the controller code is being downloaded. It will operate properly once the download is complete. Finally, the main software only reads the software versions on power-up.
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Part Number Description 7252-109 7252xi isolation manifold valve body 88-1055 7252xi isolation manifold valve coil 11-763 TFT Display 11-764 Display Inverter Electronic Board 7000-70 Sensor LED Lamp Assembly 7000-71 Sensor Photocell 7252-111 Photocell Adjustment Tool 62-293 Power Supply 23-906 7252-100-005...
SECTION 7.0 PREPARATION FOR STORAGE & SHIPMENT NOTE: The procedures given in sections 7.1 through 7.3 must be strictly adhered to in order to prevent damage to the instrument. Failure to follow these procedures will likely result in damage to the DPC during shipment. This damage is not covered by the carrier’s insurance.
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The DPC must be prepared for shipment in the following manner: 1. Ruska Instrument has an RMA procedure in place. Please contact the Customer Service Center to obtain an RMA number prior to returning any equipment to Ruska. Have the following information available when contacting Ruska: a.
FIGURE 7-1 PACKING THE DPC SHIPPING INSTRUCTIONS Ruska recommends using air freight for transportation. Surface transportation subjects the shipment to more frequent handling and much more intense shock. In most cases, if surface transportation is the mode of transport employed, handling damage is likely. Again, it is essential that the procedures mentioned in sections 7.1 through 7.3 be strictly adhered to in order to prevent any shipping and handling damage to the instrument.
APPENDIX A SUMMARY OF SPECIFICATIONS UNCERTAINTY ANALYSIS To perform an Uncertainty Analysis on a measurement device, you must be able to identify all of the parameters that influence the measurement. You must be able to quantify the magnitude of the potential error source and combine these into an overall uncertainty statement.
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could drift to its maximum stability limit at any time and therefore, reducing the calibration interval would not improve the expanded uncertainty of the device. Uncertainty of the Standard used to calibrate the transfer standard. This is the expanded uncertainty of the calibration standard that was used by the manufacturer to calibrate the digital transfer standard.
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it would be doubled to express it at the 2 sigma level (i.e. it would be an 0.01% FS device at a 2 sigma or 95% confidence level.) The following two tables are uncertainty analysis examples for a 7252i based on a three month and a yearly calibration.
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The following two tables are uncertainty analysis examples for a single range 7252 based on a three month and a yearly calibration. Uncertainty Analysis – 3 Month Calibration Interval Uncertainty Ruska Model 7252 (2 sigma) A. Performance – (Linearity, Hysteresis, Repeatability 0.003% of Full Scale...
Evacuated Reference – Option The two sigma expanded uncertainty of the vacuum sensor used to monitor the reference pressure is estimated to be less than or equal to 10 mtorr (1.33 Pa) per year. This uncertainty component should be combined RSS with the primary sensor uncertainty when operating in the absolute mode with a evacuated reference vacuum sensor.
APPENDIX B SUMMARY OF ERROR MESSAGES Negative error numbers are from the Standard Commands for Programmable Instruments (Version 1991.0). Description and Corrective Action Value No Error. -103 Invalid Separator. Check punctuation in the SCPI command. -104 Data Type. The type of parameter data is incorrect. -109 Missing Parameter.
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(section 7) if necessary. Case Pressure Overrange. Select OK, then reduce the pressure at the case reference port to 30 psia or lower. Mechanical Zeroing Needed. The zero point of the quartz Bourdon sensor is beyond the range of the compensation circuit. The zero is adjusted by the software but should be manually adjusted for complete accuracy.
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