U.S. ARMY MEDICAL DEPARTMENT CENTER AND SCHOOL FORT SAM HOUSTON, TEXAS 78234-6100 LABORATORY CENTRIFUGE SUBCOURSE MD0368 EDITION 100 DEVELOPMENT This subcourse is approved for resident and correspondence course instruction. It reflects the current thought of the Academy of Health Sciences and conforms to printed Department of the Army doctrine as closely as currently possible. Development and progress render such doctrine continuously subject to change. ADMINISTRATION Students who desire credit hours for this correspondence subcourse must enroll in the subcourse. Application for enrollment should be made at the Internet website: http://www.atrrs.army.mil. You can access the course catalog in the upper right corner. Enter School Code 555 for medical correspondence courses. Copy down the course number and title. To apply for enrollment, return to the main ATRRS screen and scroll down the right side for ATRRS Channels. Click on SELF DEVELOPMENT to open the application; then follow the on-screen instructions. For comments or questions regarding enrollment, student records, or examination shipments, contact the Nonresident Instruction Branch at DSN 471-5877, commercial (210) 221-5877, toll-free 1-800-344-2380; fax: 210-221-4012 or DSN 471-4012, e-mail [email protected], or write to: NONRESIDENT INSTRUCTION BRANCH AMEDDC&S ATTN: MCCS-HSN 2105 11TH STREET SUITE 4191 FORT SAM HOUSTON TX 78234-5064 Be sure your social security number is on all correspondence sent to the Academy of Health Sciences. CLARIFICATION OF TERMINOLOGY When used in this publication, words such as "he," "him," "his," and "men" 'are intended to include both the masculine and feminine genders, unless specifically stated otherwise or when obvious in context. USE OF PROPRIETARY NAMES The initial letters of the names of some products may be capitalized in this subcourse. Such names are proprietary names, that is, brand names or trademarks. Proprietary names have been used in this subcourse only to make it a more effective learning aid. The use of any name, proprietary or otherwise, should not be interpreted as endorsement, deprecation, or criticism of a product; nor should such use be considered to interpret the validity of proprietary rights in a name, whether it is registered or not. TABLE OF CONTENTS Lesson Paragraphs INTRODUCTION 1. PERFORM PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS) AND CALIBRATION/VERIFICATION Section I. PERFORM PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS)............................. 1-1--1-8 Section II. PERFORM CALIBRATION/VERIFICATION................ 1-8--1-10 Exercises 2. ISOLATE MALFUNCTIONS AND REMOVE AND REPLACE DEFECTIVE COMPONENTS Section I. ISOLATE MALFUNCTIONS......................................... 2-1--2-2 Section II. REMOVE AND REPLACE DEFECTIVE COMPONENTS........................................................... 2-3--1-2-4 Exercises MD0368 i CORRESPONDENCE COURSE OF THE U.S. ARMY MEDICAL DEPARTMENT CENTER AND SCHOOL SUBCOURSE MD0368 LABORATORY CENTRIFUGE INTRODUCTION The Dynac II Laboratory Centrifuge is a multipurpose unit designed for use in clinical laboratories of hospitals and medical facilities. It is used to separate the minute particles contained in fluid samples and other specimens. As a medical equipment repairer, your responsibility is to maintain, calibrate, and repair the unit to maintain maximum efficiency. This centrifuge is basically the same as all centrifuges. The difference is in the electrical circuitry. All centrifuges do the same job: some are faster, colder, and more complex. Subcourse Components: This subcourse consists of 2 lessons. The lessons are: • Lesson 1, Perform Preventive Maintenance Checks and Services and Verification/Calibration. • Lesson 2, Isolate Malfunctions and Remove and Replace or Repair Defective Components. Credit Awarded: Upon successful completion of the examination for this subcourse, you will be awarded 5 credit hours. To receive credit hours, you must be officially enrolled and complete an examination furnished by the Nonresident Instruction Branch at Fort Sam Houston, Texas. You can enroll by going to the web site http://atrrs.army.mil and enrolling under "Self Development" (School Code 555). A listing of correspondence courses and subcourses available through the Nonresident Instruction Section is found in Chapter 4 of DA Pamphlet 350-59, Army Correspondence Course Program Catalog. The DA PAM is available at the following website: http://www.usapa.army.mil/pdffiles/p350-59.pdf. MD0368 ii LESSON ASSIGNMENT LESSON 1 Perform Preventive Maintenance Checks and Services (PMCS) and Calibration/Verification. TEXT ASSIGNMENT Paragraphs 1-1 through 1-10. LESSON OBJECTIVES After completing this lesson, you should be able to: 1-1. Identify operational procedures. 1-2. Identify the steps for performing preventive maintenance checks and services (PMCS). 1-3. Identify the calibration and verification procedures. SUGGESTION After completing the assignment, complete the exercises at the end of this lesson. These exercises will help you to achieve the lesson objectives. MD0368 1-1 LESSON 1 PERFORM PREVENTIVE MAINTENANCE CHECKS AND SERVICES AND VERIFICATION/CALIBRATION Section I. PERFORM PREVENTIVE MAINTENANCE CHECKS AND SERVICES 1-1. GENERAL The DYNAC II Centrifuge is a multi-purpose machine. It is designed for use in clinical laboratories for frequently performed separations in hematology, chemistry, urinalysis, blood banking, micro-biology, and cytology. It is equally useful in the physician's and veterinarian's office, particularly where moderate-to-large numbers of Wintrobe hematocrits, urine and fecal sedimentations, and serum/plasma separations are performed. Additional applications for the centrifuge are in industrial and university laboratories for many general procedures in chemistry, pharmacology, food processing, and agriculture. Because of its compact size, the centrifuge will fit into most standard size refrigerators or can be placed in a cold room for low temperature centrifugations. 1-2. DESCRIPTION a. Safety Requirements. The Dynac II Centrifuge was designed to meet the electrical safety requirements of Underwriters' Laboratories (UL) and Canadian Safety Association (CSA). Other advanced safety features to protect the operator are also incorporated to fulfill the safety standards of OSHA. b. Guard Bowl. The centrifuge incorporates a one-piece aluminum guard bowl attached to a stable base assembly. The guard bowl, which is of heavy gauge construction, affords maximum protection to the operator. The finish is baked enamel inside and out to facilitate cleaning. c. Motor. The centrifuge motor is attached to a mounting plate which is shock-mounted to the base by means of three vibration isolators. Four rubber feet are bolted to the bottom of the base plate. The motor incorporates permanently lubricated bearings. The cord set is a 6-foot, heavy duty, 3-wire grounded cord. d. Rotors. Any of four swing-out horizontal rotors and four 52° angle rotors can be used in the centrifuge. Various shield configurations are available to accommodate tube sizes ranging from 1 milliliter (ml) to 100ml. This permits the centrifuge to be used for a variety of micro and semi-micro work. You can easily install and lock on rotors to the centrifuge shaft by means of a drive pin and thumb screw. Shield positions in all rotors are clearly numbered for positive identification of tubes. MD0368 1-2 e. Front-Panel Controls. Front-panel controls include an illuminated power switch, run-brake switch, automatic timer, adjustable speed control, and tachometer. You can continuously adjust speed over the range of 500 revolutions per minute (rpm) (minimum) to a specific maximum, depending upon the rotor and shield configuration used. f. Additional Safety Features. Additional safety features on the centrifuge include a transparent, shatter-proof, polycarbonate cover equipped with a positive latch. A latch interlock system prevents you from operating the centrifuge while the cover is open. Once the cover is closed and latched and the centrifuge is operating, a zero speed control switch prevents you from opening (unlatching) the cover until the rotor slows to less than 1 revolution per second. An external fuse, located on the back of the machine, prevents damage to the centrifuge in the event of external power surges or internal shorts. 1-3. OPERATING CONTROLS Refer to figure 1-1 for an illustration of the location of the controls on the centrifuge. Figure 1-1. Operating controls. MD0368 1-3 a. Power Switch. The illuminated power switch on the left side of the console applies power to the centrifuge. The switch remains lighted while in the ON position. b. Run/Brake Switch. The run/brake switch on the right side of the console is spring-loaded to remain in the RUN position. In this position, with the power switch on and the timer set to the desired spinning time, the motor is actuated to begin the centrifuge cycle. When you manually hold down the switch in the BRAKE position, the switch actuates an electric brake which will bring the rotor to a gentle stop in less than 30 seconds. To actuate the brake, perform the following: (1) Press and hold the switch down. The brake will be activated as long as the switch is held down. (2) Release the switch as soon as the rotor comes to a stop. NOTE: For delicate sedimentations, release the switch just before the rotor comes to a stop and let the rotor coast gently to a stop. (3) DO NOT HOLD THE BRAKE SWITCH DOWN AFTER THE ROTOR HAS STOPPED. If you hold it down too long, the rotor will automatically begin accelerating in the opposite direction. NOTE: Unless the timer runs out or is turned to "0," the rotor will regain speed when the switch is released. c. Speed Control. A solid-state speed control provides smooth control over a wide range of rpm. With the timer set, the power switch in the ON position, and the centrifuge rotating at minimum speed, perform the following: (1) Gradually turn the speed control knob clockwise from "0" until the desired speed is indicated on the tachometer. (2) At the end of the centrifugation cycle, return the speed control knob counterclockwise to "0." (3) You may select any speed from minimum ("0") to the maximum velocities indicated in figure 1-2 for each of the fourteen rotor/shield configurations. NOTE: Before operating the centrifuge, the speed control should always be set at "0." Depending on the rotor configuration and load, the centrifuge will rotate at less than 500 rpm with the speed control set at "0." MD0368 1-4 Cat. No. 0261 Cat. No. 0273 4-place 15ml horizontal rotor with 4-0901 4-place horizontal rotor with 4 multiple shields. carriers for 20 13x100mm tubes (0922) TIP RADIUS-6.8 inches TIP RADIUS-6.0 inches MAX SPEED-2690rpm MAX SPEED-2650rpm RCF-1397 RCF-1197 Cat. No. 0263 Cat. No. 0281 4-place 50ml horizontal rotor with 4-0900 6-place 15ml angle rotor with 6-0901 shields. shields. TIP RADIUS-6.94 inches TIP RADIUS-6.37 inches MAX SPEED-2560rpm MAX SPEED-2760rpm RCF-1292 RCF-1378 Cat. No. 0265 Cat. No. 0283 8-place 15ml horizontal rotor with 8-0901 4-place 50ml angle rotor with 4-0900 shields. shields. TIP RADIUS-7.03 inches TIP RADIUS-6.49 inches MAX SPEED-2340rpm MAX SPEED-2860rpm RCF-1093 RCF-1508 Cat. No. 0267 Cat. No. 0285 4-place 100ml horizontal rotor with 4-0908 12-place 15ml angle rotor with 12-0902 shields. shields. TIP RADIUS-7.13 inches TIP RADIUS-5.75 inches MAX SPEED-2450rpm MAX SPEED-2890rpm RCF-1215 RCF-1364 Figure 1-2. Maximum angular velocities and relative centrifugal Forces for Dynac II Centrifuge rotors (Model 0103 at 120 volts alternating current (vac), 60 hertz (Hz) and Model 0106 at 220vac, 50 Hz). (Continued) MD0368 1-5 Cat. No. 0269 & 0271 Cat. No. 0287 4-place horizontal rotor with 4 multiple 12-place 15ml horizontal rotor with 12-0901 carriers for 36 10x75mm tubes or shields. 28 12x75mm tubes (0920 & 0921). TIP RADIUS-5.0 inches TIP RADIUS-6.37 inches MAX SPEED-3600rpm MAX SPEED-2610rpm RCF-1840 RCF-1232 Cat. No. 0289 Cat. No. 0293 24-place 15ml angle rotor with 24-0902 24-place angle rotor with 24-0904 shields. shields. TIP RADIUS-5.75 inches TIP RADIUS-5.0 inches MAX SPEED-2760rpm MAX SPEED-3400rpm RCF-1244 RCF-1641 Cat. No. 0291 24-place 15ml angle rotor with 24-0901 shields. TIP RADIUS-6.37 inches MAX SPEED-2500rpm RCF-1131 Figure 1-2. Maximum angular velocities and relative centrifugal Forces for Dynac II Centrifuge rotors (Model 0103 at 120 volts alternating current (vac), 60 hertz (Hz) andModel 0106 at 220vac, 50 Hz). (Concluded) d. Timer. Spinning time is controlled by a 30-minute timer with a hold position for continuous operation. Operating the timer automatically turns on the centrifuge, provided the power switch is on and the cover is securely latched. (1) To set the timer, turn the knob clockwise to the desired setting. The centrifuge will now operate to the end of the timed cycle and then shut off automatically. (2) For continuous operation, turn the knob clockwise, to the HOLD position. The centrifuge will now operate continuously until it is manually shut off. To shut off, turn the knob counterclockwise to "0." MD0368 1-6