INSTRUMENT

MAINTENANCE
 Introduction
 Reliable instrument and equipment performance is
one of the objectives of a comprehensive well
structured quality assurance program.
 Proper management of the equipment in the
laboratory is necessary to ensure accurate, reliable
and timely testing.

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 The Benefits of a Good Equipment
Management Program
 Helps to maintain a high level of laboratory performance.
 Reduces variation in test results, and improves the
technologist’s confidence in the accuracy of testing
results.
 Lowers repair costs, as fewer repairs will be needed for a
well-maintained instrument.
 Lengthens instrument life.
 Reduces interruption of services due to breakdowns and
failures.
 Increases safety for workers.
 Produces greater customer satisfaction.
 Program Monitoring
 It is the responsibility of the laboratory director to:
 oversee all the equipment management systems in the laboratory;
 ensure that all persons who will be using the instruments have
been:
 appropriately trained and understand how to both properly operate the
instrument and
 perform all necessary routine maintenance procedures.
 Equipment management responsibility may be specifically
assigned to a technologist in the laboratory.
 In many laboratories, there is a person who has good skills with
equipment maintenance and troubleshooting.
 Giving this person the role of oversight of all equipment is
recommended.
 Program Considerations
 A great deal of thought and planning should go into
equipment management.
 As the laboratory puts an equipment management program
in place, the following elements should be considered:
 Selection and purchasing
 Installation
 Calibration and performance evaluation
 Maintenance
 Troubleshooting
 Service and repair
 Retiring and disposing of equipment
 Program Considerations
Selection and Purchasing
 Selecting the best instrument for the laboratory is a very
important part of equipment management.
 Some criteria to consider when selecting laboratory
equipment are listed below:
 What are the performance characteristics of the instrument?
 Is it sufficiently accurate and reproducible to suit the needs of the
testing to be done?
 What are the facility requirements, including the
requirements for physical space?
 Will the cost of the equipment be within the laboratory’s
budget?
 Will reagents be readily available?
 Program Considerations
Selection and Purchasing
 How easy will it be for staff to operate?
 Is there a retailer for the equipment in the country, with
available services?
 Does the equipment have a warranty?
 Are there any safety issues to consider?
 If decisions are made outside the laboratory, the lab.
manager should provide information that will support
selecting equipment that will best serve the needs of the lab.
 If donors are likely to provide some of the equipment that is
used, lab. management should have input into the choice of
equipment otherwise management should consider declining
equipment if it is inappropriate for laboratory needs.
 Program Considerations
Selection and Purchasing
 Is it better to purchase or lease equipment? When making
this decision, it is a good idea to factor in repair costs.
 The manufacturer should provide all of the necessary
information to operate and maintain equipment.
 The initial cost of an instrument may seem reasonable,
but it may be expensive to repair.
 Program Considerations
Selection and Purchasing
 Before purchasing ask if:
 Wiring diagrams, computer software information, a list of parts
needed, and an operator’s manual are provided;
 The manufacturer will install the equipment and train staff (covering
travel expenses as necessary) as part of the purchase price;
 The warranty includes a trial period to verify that the instrument
performs as expected;
 The manufacturer’s maintenance can be included in the contract and,
if so, whether maintenance is provided on a regular basis.
 Determine if the laboratory can provide all the necessary physical
requirements, such as electricity, water, and space.
 There must be adequate room to move the equipment into the
laboratory; consider door openings and elevator access.
 Program Considerations
Calibration and Performance Evaluation

 Follow the manufacturer’s directions carefully when

performing the initial calibration of the instrument.
 It is a good idea to calibrate the instrument with each
test run, when first putting it into service.
 Determine how often the instrument will need to be
recalibrated, based on its stability and the
manufacturer’s recommendation.
 It may be advantageous to use calibrators provided
by or purchased from the manufacturer.
 Program Considerations
Calibration and Performance Evaluation

 Prior to testing patient specimens, it is important to evaluate

the performance of new equipment to ensure it is working
correctly with respect to accuracy and precision.
 Laboratories need to verify the manufacturer's performance
claims, and demonstrate they can get the same results using
the kits or equipment in their laboratory, with their personnel.
 Some of the steps that should be followed to verify
performance include:
 testing samples with known values and comparing the results to
the expected or certified value;
 if equipment is temperature controlled, establishing the stability
and uniformity of the temperature.
 Program Considerations
Calibration and Performance Evaluation

 In order to verify that equipment is working according to

the manufacturer’s specifications, it is necessary to monitor
instrument parameters by performing periodic function
checks.
 This should be done before using the instrument initially,
then with the frequency recommended by the manufacturer.
 These function checks should also be done following any
instrument repairs.
 Some examples of function checks are daily monitoring of
temperatures and checking the accuracy of wavelength
calibration.
 Program Considerations
Preventive Maintenance
 Preventive maintenance includes measures such as systematic
and routine cleaning, adjustment and replacement of equipment
parts at scheduled intervals.
 Manufacturers generally recommend a set of equipment
maintenance tasks that should be performed at regular intervals:
daily, weekly, monthly or yearly.
 Following these recommendations will ensure that the equipment
performs at maximum efficiency and will increase the lifespan of
the equipment. This will also help to prevent:
 inaccurate test results due to equipment failure
 delays in reporting results
 low productivity
 large repair costs.
 Program Considerations
Troubleshooting
 Manufacturers frequently provide a flowchart that can
help determine the source of problems.
 Some of the questions to consider are listed below.
 Is the problem related to a poor sample? Has the sample
been collected and stored properly? Are factors such as
turbidity or coagulation affecting instrument performance?
 Is there a problem with the reagents? Have they been stored
properly, and are they still in date? Have new lot numbers
been introduced without updating instrument calibration?
 Is there a problem with the water or electrical supply?
 Is there a problem with the equipment?
 Equipment Maintenance
Documentation
 Equipment documents and records are an essential part of
the quality system.
 The policies and procedures for maintenance should be
defined in appropriate documents, and keeping good
equipment records will allow for thorough evaluation of
any problems that arise.
 Equipment Maintenance
Documentation
 Each piece of equipment should have a dedicated
logbook documenting all characteristics and
maintenance elements, including:
 preventive maintenance activities and schedule;
 recording of function checks and calibration;
 any maintenance performed by the manufacturer;
 full information on any problem that the instrument
develops, the subsequent troubleshooting activity and
follow-up information regarding resolution of the
problem.
 Equipment Maintenance
Documentation
 In recording problems, be sure to record
 date problem occurred and when equipment was removed
from service;
 reason for breakdown or failure;
 corrective action taken, including a note about any service
provided by the manufacturer;
 date returned to use;
 any changes to procedure for maintenance or function
checks as a result of the problem.
QUALITY ASSURANCE OF
REAGENTS, SUPPLIES, AND
LABORATORY WATER
 Introduction
 In order to produce high quality work, a laboratory
requires a constant supply of good quality
reagents, supplies and water
 A deficiency of any of these can cause the most
efficient laboratory either to come to a standstill or
to provide substandard service

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 Choice and Evaluation of
Reagents and Supplies
 A selection of a brand of reagent for instrument
system or laboratory tests is made after searching
and gathering information concerning the reagent
sensitivity, preparation, storage, and cost
 Next, an evaluation of the selected material is
performed in the laboratory, comparing the new
reagent to the old
 If the comparison is favorable, the new reagent is
purchased

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 Choice and Evaluation of
Reagents and Supplies
 Before committing to purchase insists on
performing a field trial of the reagent
 Factors that should be considered in selecting and
evaluating a new reagent or material supplies are:
1. Sensitivity
2. Stability and storage conditions
3. Vendor reputation
4. Delivery time
5. Cost

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Reagents Prepared in the Lab.
 Reagents, standards and controls prepared in the
laboratory from stock chemicals should be:
 Prepared using class A volumetric glassware and properly
calibrated balances
 To eliminate variation (batch to batch), preparation should be
limited to one or two persons
 Label each reagent, standard, and control with the
following:
 The name of the material
 The procedure for which the material is to be used
 Date of preparation
 Date of expiration
 Initials of the person who prepared it
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 Laboratory Water
 Reagent - grade water must be properly purified and
periodically inspected for:
1. Electrical resistivity
 Resistivity (R) of water is the measurement of electrical
resistance and is the inverse of electrical conductivity (C)
 R and C are directly related to the number of inorganic ions and
conduction particles in the water
 The greater the ionic concentration, the greater the electrical
conductivity and the less the electrical resistance
 Measurements are made using a resistivity or conductivity meter
2. Soluble silica concentration
 Measured by a chemical reaction between silicate and molybdate
ions to form a blue complex, intensity is proportional to conc.
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 Laboratory Water
3. Desired pH
 The pH is measured with pH meter. Pure water contains so few ions
that measurement of pH is not necessary if resistivity is very high
4. Bacterial contamination
 The microbiological content of the water is defined as the number of
colony - forming units per milliliter of water
 Three recommended methods:
 Pour plate (1 ml of water)
o Add 1 ml of well mixed water to a nutrient-supplemented medium
and incubate for 24h at 36 ± 1oC
 Membrane filtration
o Using a sterile vacuum membrane filter system to filter microbes,
then incubate the filter on medium for 24h at 36 ± 1oC
 Calibrated loop for sampling (0.01 ml)
o Inoculate agar plate. Incubate for 24h at 36 ± 1oC 25
 Laboratory Water
 Purification of water can be achieved through 3 methods:
 Distillation
 Deionization
 Reverse osmosis
 Additional purity is obtained with charcoal filtration.

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 Laboratory Water
Water Grades According to Purity

 Type I water:
 The highest level of purity,
 used for:
 tissue and cell culture methods
 special and critical analytical chemical analysis
 and in preparation of standard solutions

 Type II water:
 Used for most routine quantitative clinical laboratory
methods
 It should be stored for short periods of time before use, to
prevent change in resistivity and bacterial growth
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 Laboratory Water
Water Grades According to Purity

 Type III water:

 The least pure
 Suitable for most qualitative procedures including:
 Urine analysis
 parsitology
 and histology
 Suitable for glassware washing
 Stored in containers that protect it form contamination

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 Laboratory Water
Water Grades According to Purity

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Laboratory Inventory
Management
 Introduction
 Purchasing and inventory management is a critical
and essential component of the quality management
system.
 Efficient and cost-effective laboratory operations
need the uninterrupted availability of reagents,
supplies and services.
 Inability to test, even for a short time, is very
disruptive to clinical care, prevention activities and
public health programs.
 Goals of Laboratory Inventory
Management
 Effective inventory control involves setting up a
system that has the following goals:
 Improve communication between the laboratory and
the other hospital departments involved in
purchasing, stocking, and paying for supplies
 Manage inventory so that shortages and overstocking
should be avoided
 Teaching laboratory employees better budgeting and
materials management techniques

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 Inventory Control Program

 Designing and implementing an inventory control

program involves :
 The identification of the needed supplies
 Their rate of use
 Periodic review and evaluation of the inventory and
ordering process
 Inventory Control Program

 Conduct a survey to list all of supplies that the laboratory

uses, the list should include:
 The name of the item
 A brief description
 Approximate usage per month
 Current vendor
 Order unit amount
 Current unit packing, that is per box, carton, or bag
 Order or catalogue number
 Priority of need
 Assigning an item its relative importance
 High priority: if needed constantly or cannot be done without
 Medium priority: if needed occasionally
 Low priority: if needed rarely
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 Inventory Control Program

 The next step is to determine the order point, order

quantity and lead time for the item
 Order point:
 The sum of the minimum inventory plus the emergency
supply
 The level of inventory at which an order is generated
 The minimum inventory is the amount of the material
necessary to perform the routine work until the next
shipment arrives
 The emergency supply is a reserve of supplies held aside to
meet an unexpected increase in the workload or a delay in
delivery of the new order
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 Inventory Control Program

 Determination of the order point and order quantity will

depend on the space the lab. Has available for storage, its
rate of use and the lead time of the material
 Lead Time:
 is the length of time between initiating an order and
receiving it in the laboratory
 Inventory Control Program

 Controlling inventory involves the counting, storage

and movement of supplies within the laboratory
 A written record system of inventory levels and
checks should be devised
 Three types of record systems are suggested:
1. The periodic count
 Strict inventory control is not required
 Count of materials weekly or every two weeks, when count
reaches the order point, an order is generated
 Good for small to midsize Lab.

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 Inventory Control Program

2. The continuous inventory record

 Strict inventory control is required
 Inventory is closed to lab. Personnel, one or two persons
manage it
 Good for larger lab.
3. The specialized inventory record
 Used for slow-moving, infrequently ordered parts such as
instrument spare parts
 Parts are not ordered until inventory is used

 Once the inventory system has been set up, it should

be reviewed annually for updating
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