Validation of a Laboratory I ncubator U sing Wireless and Cabled

T he following article describesthe various steps regardingthe Installation Qualification

(IQ), Operational Qualification (OQ)and Performance Qualification (PQ)that were executed to complete thevalidation of a pharmaceutical micro-biology laboratory incubator. Thisvalidation was designed and per-formed from the viewpoint of amicrobiologist with assistance fromvalidation experts. The protocol usedfor this validation was previouslypublished in the Journal of Valida-tion Technology.1

Descr iption of the I ncubator Unit

The incubator is a conventional unit where freshair enters though an air intake at the bottom. The airis heated at a plenum below the chamber and flowsinto the chamber in a uniform flow pattern. Exhaustair is vented through a port at the top of the incubator.The unit is a Precision Thelco Incubator catalog num-

ber 31487. This is a gravity convec-tion unit model number 6M with anoperating temperature range of 25¼Cto 70¼C. The incubator has the fol-lowing electrical characteristics:

Volts- 120Hertz- 50/60Watts- 300

The overall dimensions of theunit are 42 X 21 X 39Ó with cham-ber dimensions 36 X 18 X 27Ó. T h eincubator contains a dual hydraulicthermostat, a mercury-in-glass ther-

m o m e t e r, two shelves, two heaters, double innerdoors, and double outer doors.

Installation Qualification (IQ)During the IQ, personnel documented all items list-

ed in the Incubator IQ Form. Refer to Appendix A o fvalidation protocol, previously published in theJournal of Validation Te ch n o l og y.1 A second personreviewed and approved all verifications.

}T his validationwas designed

and per for medfr om the

viewpoint of amicr obiologist

with assistancefr om validation

exper ts. ~

V alidation of a L abor ator yI ncubator U sing W ir eless

and C abled D atalogger

– P ar t I I –By Laura Valdes-Mora

Elite MicroSource Corporationand Pamela Hardt-English

PhF Specialists, Inc.

v

Laura Valdes-Mora & Pamela Hardt-English

PurposeIQ was conducted to demonstrate that the piece

of equipment was inspected, and contains all therequired parts for its proper functioning. The pres-ence/absence of external equipment aides (recordercharts, etc.) was also documented.

E quipment and Materials¥ Incubator¥Appendix A

IQ Observations¥Incubator Description Ð The unit is a Precision

Thelco Incubator, catalog number 31487. Thetemperature range it is designed for is fromroom temperature to 70¼C. The unit uses 120volts and 5.2 amps. This incubator had not beenpreviously validated, and was 29 years andseven months old at the time this validation wasconducted.

¥ Incubator Model Number is 6M. ¥ Incubator Serial Number Ð 22-AG-8.¥Incubator was purchased on July 14, 1971 from

Precision Scientific.¥Vendor Manual is available.¥Location of Vendor Manual Ð The manual can be

found in the file cabinet of the microbiology lab-o r a t o r y.

¥Drawings for the incubator are available andlocated in the vendor manual.

¥ Utilities required Ð Electricity is required for thisunit. The power source was found to be presentand functional. A member of the maintenancedepartment measured the Volts and the amper-age reading of the circuit of the electrical outletwhere the incubator is plugged in. The data wererecorded Òas found.Ó

Utility DataCircuit Rating:130 Vo l t s 1 Phase 60 Hertz 20 A m p sEquipment Rating:125 Vo l t s 1 Phase 60 Hertz 5.2 A m p sField Measurement:122.9 Vo l t s 1 Phase 60 Hertz 4.8 A m p s

Cord and Plug NEMA Designation: 5-15 PWall receptacle NEMA Designation: 5-15R

Notes: The ground wire is connected. Non-loadcycle Amps = 0.5

¥ An Uninterrupted Power Supply (UPS) is notused on this incubator.

¥This unit is not hooked to a back-up generator.¥ List of Standard Operating Procedures (SOPs)

associated with this incubator; the SOPs were list-ed by number, title, and revision number. T h e yare not included in the article as SOPs, and areconfidential documents of the company where weconducted this validation. SOPs were reviewedand were found to be appropriate.

¥The incubator does not have a temperature display.¥ There is an external temperature recorder in use

for this unit, which is a Dickson Temptrace Re-corder Chart. The recorder chart is identified asnumber one and contains a replaceable seven-daychart (graph).

¥Acceptance criteria were met.

Operational Qualification: (OQ)In this section the performance of the equipment

and its operational procedure was verified. The OQof an incubator consists of an empty chamber tem-perature mapping.

PurposeThe OQ was performed to confirm that the empty

chamber works within the specified limits of tem-perature (32 to 37¼C) throughout the chamber.

E quipment and Materials¥ Precision Thelco Incubator (32-37¼C)¥Real Time Datalogger - Ellab Model TM9616

Real Time DataloggerSerial Number Ð 00270110141

¥Thermocouples Ð Type Ð T (Cu/Con)¥Wireless Data Loggers Ð

Ellab Model T S M 9 8 0 3Serial Number 2056Temperature Sensor Serial NumberLC 1 20022 6422LC 2 20753 5757LC 3 20770 5747LC 4 20764 5770LC 5 20804 5766LC 6 20717 5309


LC 7 20713 5219LC 8 20703 4521LC 9 11542 5679LC 10 11537 4553

¥Windows-based PC or laptop computer to oper-ate data loggers

¥ External Temperature Device ¥Timer

E quipment PictureSee Figure 1.

Acceptance CriterionAll sites measured are within 32-37¼C.

OQ ObservationsCalibration

The calibration of thermocouples was performedusing a Kaye LTR-140 serial number 5C339H, ownedby the pharmaceutical company where we conductedthis validation. A total of 12 Thermocouples (TCs)were tested, and 10 of those were used for the tem-perature profiles. Calibrations were satisfactorily con-ducted according to the SOPs. The two extra calibrat-ed thermocouples were kept in reserve in case of afailure of one of the others.

Location of Thermocouples and Loggers- Dia-grams: The purpose of the diagram is to show therelative position of the thermocouples and wirelesssensors. The figure is not to scale.

In the diagrams seen for the top and lower shelf,each number corresponds to the thermocouple andthe logger placed at the location. The two deviceswere side-by-side for each one of the locations indi-cated. The box in the lower shelf with an R in thecenter indicates the location of the chart recorder, asshown in Figure 2.

Tests for Temperature SettingThe incubator was set to 35-37¼C or 36 + 1 ¼ C .

While TCs were being placed, the incubator wasopened for 20 minutes. It took 30 minutes after clos-ing the doors of the incubator for the unit to reach35¼C. Note that the chart recorder was reading 32.4¼C.An additional reading of the recorder indicated thetemperature to be 35.5¼C.

Test of temperature setting number one (lowesttemperature setting on this incubator). In order toexpedite the decrease in temperature, we opened thedoor of the incubator for a few minutes. The temper-ature decreased to a range between 25-29¼C. A f t e rclosing the door and allowing T C Õs to stabilize, thelowest temperature recorded was 29¼C, as shown inFi g u re 3.

Test of Temperature Setting #9 (highest safetemperature setting on this incubator). Safety lightcame on at 66¼C. Chart recorder read 49.9¼C, whilethe TC next to the recorder chart read 59.2¼C as

Figure 2

R elative P os ition of theT hermoc ouples and

Wireles s S ens orsTop S helf

L ower S helf

Front

Front

1 2

3

4 5

6 7

8

9 10

R

Figure 1

E mpty C hamber S et-Up

E mpty


shown in Fi g u re 4. It appears that the chart recorderresponds more slowly than the thermocouples totemperature changes.

Due to the fact that the safety light came on duringthis test, it was decided to record current tempera-tures, and set the knob back to its regular setting ofnumber five. The incubator manual was reviewed,and it was found that the safety light is related to asafety thermostat, which operates alternatively to thecontrol thermostat.

After increasing the temperature as per step num-ber three, it took the incubator 75 minutes to comedown to the set temperature range of 35-37¼C.

Once all thermocouples were within the tempera-ture range established by the protocol (32-37¼C),with the understanding that temperature readingscan range from 31.5 up to 37.4¼C (per roundingrules), the 24-hour mapping study was started.

24-Hour Temperature MappingThe empty chamber test was conducted for over

24 hours. Temperature readings were recorded everytwo minutes. From the time the run was started(02:10:40 PM) to its end, the time was determined to

be 26 hours, 44 minutes, and 39 seconds.At 03:52:40 PM, all TCs were within temperature

range. There were still some hot pockets left fromthe previous study. It took the chamber an addition-al 42 minutes to stabilize all locations.

The data obtained show that all thermocoupleswere within the specified temperature range for 24hours as shown in Figure 5.

Wi reless Datalogge r, Tra ck s e n s e : The study start-ed at 08:43:00. All wireless loggers (LCs) were at thet a rget temperature range at 10:07:00 as shown inFi g u re 6. It took the sensors 1 hour and 24 minutes toall be stabilized. This is almost double the amount oftime it took the T C Õs to get into temperature range.

Figure 3

R es ults of L o wTemperature S etting

4 0 . 0

3 5 . 0

3 0 . 0

2 5 . 0

2 0 . 000.32 00:37 00:42

S etting

TC 1 Top Shelf Back LeftTC 2 Top Shelf Back RightTC 3 Top Shelf CenterTC 4 Top Shelf Front LeftTC 5 Top Shelf Front RightTC 6 Bottom Shelf Back LeftTC 7 Bottom Shelf Back Right

TC 8 Bottom Shelf CenterTC 9 Bottom Shelf Left Fr o n tTC 10 Bottom Shelf Front RightTC 13 DescriptionTC 14 DescriptionTC 15 DescriptionTC 16 Description

Figure 4

R es ults of High Temperature S etting

7 0 . 0 0

6 0 . 0 0

5 0 . 0 0

4 0 . 0 0

3 0 . 0 0

2 0 . 0 0

1 0 . 0 0

0 . 0 0

01:08 01:13 01:18 01:23S etting




In order for this to be a 24-hour run, the readingsneeded to last until 10:07:00 on day number two. T h elast reading on day number two was made at08:41:00, which completes the 24-hour run, but doesnot map the temperature within specified ranges for24 hours. This is one hour and 20 minutes short of therequirement. This is due to the fact of not being ableto see the data until the study is complete. Note thatthe wireless system is being used to determine itssuitability for validating incubators by comparing itto the real time system. This validation study is basedon the data obtained from traditional thermocouples.

Thermocouple Test: Started at 2:40:40 and endedat 26:52:40.

All TCs reached the target temperature range at2:40:40. During the first hour and eight minutes, therewere 10 temperature excursions: one on TC 5 of0.1¼C and the other seven on TC 8. Of the excursionson TC 8, six were of 0.1¼C, and one was of 0.2¼C.This was not observed at any other point in time dur-ing the 24-hour study. This indicates that there werestill a few hot spots in the chamber after the highest

temperature setting test was completed immediatelyprior to the empty chamber mapping. Future mappingstudies should allow for more time between testseither by adding two extra hours, or by running themapping study for 30 hours in order to compensatefor the adjustment period. There are companies thatchange temperature ranges of their incubators on aregular basis, due to the variety of tests conducted andthe lack of incubators. In this situation, the chambershould be allowed several hours to equilibrate prior toloading it. However, this is not the case of this partic-ular piece of equipment. Therefore, this phenomenonobserved during the 24-hour empty chamber testshould not occur during day-to-day use.

Tracksense: All wireless sensors were withinspecified temperature range at 9:43:00. During thefirst 24 minutes, three sensors reached 37.5¼C. Thiswas not observed at any other point in time duringthe 24-hour study.

During the review of TC temperatures, the excur-sions stated above were not found. The highest tem-perature found during this review using the comput-er screen was 37.1¼C

Figure 5

R es ults of 24-Hour E mptyC hamber Mapping

T hermoc ouples4 0 . 0

3 0 . 0

2 0 . 0

1 0 . 0

0 . 002:40 07:25 12:10 16:55 21:40

S etting



Figure 6

R es ults of 24-Hour E mptyC hamber Mapping Wireles s Trac ks ens e

4 0 . 0

3 0 . 0

2 0 . 0

1 0 . 0

0 . 008:43-1 13:28-1 18:13-1 22:58-1 03:43-2

S etting

LC 1 Top Shelf Back LeftLC 2 Top Shelf Back RightLC 3 Top Shelf CenterLC 4 Top Shelf Front LeftLC 5 Top Shelf Front Right

LC 6 Bottom Shelf Back LeftLC 7 Bottom Shelf Back RightLC 8 Bottom Shelf CenterLC 9 Bottom Shelf Left Fr o n tLC 10 Bottom Shelf Front Right


All temperature devices were checked, and all werewithin the specified limit of + 2¼C from each other.

Note that the temperature loggers recorded diff e r e n tactual clock times. The loggers were not synchronizedfor this study, neither were they set to local time. Eachone was set for a different time zone. Areal time elapsedadjustment was made to account for the diff e r e n c e .

Performance Qualification: (PQ)In this section it was verified that the loaded incu-

bator chamber was capable of reaching and main-taining the target temperature range.

PurposeThe PQ confirms that the loaded chamber works

within the specified limits of temperature through-out the chamber. The effect of opening doors for twodifferent lengths of time, and the effect of a powerfailure on the incubatorÕs ability to get back into thetemperature profile were also evaluated.

E quipment and Materials¥ Precision Thelco Incubator (32-37¼C)¥Real Time Data Logger Ð Ellab Model TM9616

Real Time Data Logger Serial Number Ð 00270110141

¥Thermocouples Ð Type Ð T (Cu/Con)¥Wireless Data Loggers

Ellab Model TSM9803Serial Number 2056Temperature Sensor Serial NumberLC 1 20022 6422LC 2 20753 5757LC 3 20770 5747LC 4 20764 5770LC 5 20804 5766LC 6 20717 5309LC 7 20713 5219LC 8 20703 4521LC 9 11542 5679LC 10 11537 4553

¥ Windows-based PC or laptop computer tooperate data loggers.

¥External Temperature Device (chart recorder)¥Timer¥Agar plates and culture broths to create a maxi-

mum loaded chamber pattern.

Acceptance CriterionAll sites measured are within 32-37¼C

PQ ObservationsA maximum load pattern was selected for the

PQ. In addition, the effect of opening doors for twod i fferent lengths of time, and the effect of a powerfailure on the temperature profile were evaluated inthis phase. Ty p i c a l l y, these evaluations are con-ducted during the OQ, however, we chose theloaded chamber for these tests as we consider thisscenario more realistic, therefore, more meaning-f u l .

Loaded Chamber DescriptionTop Shelf:

4* 2000 mL screw cap bottles of LactoseB r o t h

4 1000 mL screw cap bottles contain-ing 500 mL each of Lactose Broth

1 Rack of 40 screw cap test tubes with10 mL each of Nutrient Broth

2 Baskets each containing 11 Whirlpakbags each with 100 mL TSB**

Lower Shelf:1 Chart recorder1 Water bottle (used by laboratory for

temperature determinations)15 Stacks of plates- total of 72 plates- 42

Blood Agar and 30 TSA***12 Whirlpak bags with 250 mL Lactose

Broth each (in a basket)4 API strips

* Two (2) 2000 mLbottles were removed fromthe study. See observations for explanation.

** TSB= Tryptic Soy Broth*** TSA= Tryptic Soy Agar

Loading Pattern Diagrams: The purpose of thediagrams in Figure 7 is to show the relative positionof the various items in the load. The diagrams arenot to scale.

Numbers on each of the above rectangles denotenumber of plates on each stack. If the number is fol-lowed by mL, it denotes the volume of medium oneach container.


Loaded Chamber PictureAn example of a loaded chamber can be seen in

Figure 8.

Maximum Load PatternAfter loading the chamber and waiting one hour

and 45 minutes, it was observed that only 2 TCs werewithin the target temperature range. We analyzed thecontent of the load, and laboratory personnel re-viewed the loading pattern. It was concluded that theincubator was loaded above the worst-case scenario.Four 2-liter flasks are never placed into this incubatorby laboratory personnel. This was done only onceduring the validation of a microbial limit test, but as itis not a regular procedure, it was chosen to decrease

the loaded chamber by two 2-liter flasks, based onpreviously performed work.

Following this action, it took the chamber twohours and 45 minutes to reach the set temperature.

Five-Minute Opened Door TestThis incubator consists of two double doors.

During this test all doors were opened for five-min-utes. The purpose of the test is to simulate a worse casescenario when laboratory analysts are loading inocu-lated samples and their controls into the incubator.

During this test time, the temperature of the incu-bator decreased. Temperature ranged from 22.9 to30.2¼C across the loaded chamber as shown in Fig-ure 9. The chart recorder reading was 30.5¼C. It took50.5 minutes for the loaded chamber to return to theset temperature.

Three-Hour Power Outage TestThe purpose of the test was to simulate the eff e c t

of a power outage on the temperature profile of afully loaded incubator chamber. The TCs werechecked to ensure all sites were at the set temperatureand proceeded to disconnect the incubator. A f t e rthree hours, the temperature across the chamber wasreviewed and the incubator was reconnected to itspower supply.

There was a decrease in temperature that took theloaded chamber outside the set temperature and out-side the target temperature. Temperatures rangedfrom 27.7 to 29.4¼C as shown in Fi g u re 10. The chartrecorder was reading 28.7¼C.

Figure 7

R elative P os ition of the VariousItems in the L oad

B ottom S helf

T1 T2

T3

T4 T5

T6 T7

T8

T9 T 1 0

2000mL

Top S helf

2000mL

Test TubeRack

10A

10B

3A

4B

4A

5A

4B4

B4B

6B

8A

R C

2 B

2 B3 B

3 B

Basket#1

1000

mL

1000

mL

1000

mL

1000

mL

Basket#2

Basket

API

R= Chart recorderA= TSA platesC= Water ControlB= Blood Agar Plates

T= Thermocouple number (awireless sensor is next toeach thermocouple)

Figure 8

P ic ture of F ully L oaded C hamber

F ull


Following the power start-up, it took one hourand 35.5 minutes for the temperature to reach the setpoint of 35-37¼C. This unexpectedly long ramp timesignals that the load also dropped in temperature,thus requiring a longer time to return to the set tem-perature.One-Minute Opened Door Test:

The protocol was originally written for a five-minute and a 15-minute opened door test. After per-forming the five-minute opened door test, it wasdetermined that most of the time the incubator doorsdo not remain open longer than just a few minutes,typically not even reaching the five-minute mark.Based on this, it was decided to change the 15-minute test to a one-minute test in order to representa true scenario. In addition, for this test, only one side

of the double doors was opened, not both, for thesame reason of mimicking actual use.

During the one-minute opened door test, the tem-perature decreased and was outside the set tempera-ture in some areas of the chamber. The temperaturesranged from 29.3 to 35.2¼C as shown in Fi g u re 11.The chart recorder was reading 33.6¼C. It took 15 min-utes for the chamber to return to the set temperatureonce the door was closed.

24-Hour Loaded Chamber Temperature MappingThe loaded chamber test was conducted for 24

hours. Temperature readings were recorded everytwo minutes. The study started at 08:32:00 and endedat 32:16:00. This is 16 seconds short of precisely 24-hours, however, due to rounding rules, this small

Figure 10

R es ults of T hree-Hour Power Outage Tes t

7 0 . 0 0

6 0 . 0 0

5 0 . 0 0

4 0 . 0 0

3 0 . 0 0

2 0 . 0 0

1 0 . 0 0

0 . 0 003:36 04:31 05:26 06:21 07:16

S etting

TC 1 Top Back LeftTC 2 Top Back RightTC 3 Top CenterTC 4 Top Front LeftTC 5 Top Front Right

TC 6 Bottom Back LeftTC 7 Bottom Back RightTC 8 Bottom CenterTC 9 Bottom Front LeftTC 10 Bottom Front Right

Figure 9

R es ults of F ive-Minute Opened Door Tes t

7 0 . 0 0

6 0 . 0 0

5 0 . 0 0

4 0 . 0 0

3 0 . 0 0

2 0 . 0 0

1 0 . 0 0

0 . 0 002:34 02:44 02:54 03:04 03:14 03:24 03:34

S etting

TA 1 Top Back LeftTA 2 Top Back RightTA 3 Top CenterTA 4 Top Front Left

TA 5 Top Front RightTA 6 Bottom Back LeftTA 7 Bottom Back RightTA 8 Bottom Center


shortage is considered acceptable as this is a 24-hourrun, not a 24.0-hour run.

All thermocouples were within temperature rangeat the start of the mapping, as shown in Fi g u re 12.

No excursions were found at any point in time,thus corroborating that the excursions seen duringthe empty chamber test were due to hot pockets leftfrom the highest temperature setting test.

The loaded chamber maintained a tight temperaturerange throughout the 24-hour mapping study on a perTC basis. The lowest temperature recorded was34.5¼C found on TC 8, while the highest was 36.9¼Cfound on TC 9.

Tra ck s e n s e : All loggers were within temperaturerange at the start of the mapping as shown in Fi g u re1 3. The study started at 09:50:00, and ended at33:52:00, for a total of 24 hours and two seconds.There were no excursions found at any point in time.

The lowest temperature recorded was 34.3¼C found onLC 8, while the highest was 37.0¼C found on LC 6.

All temperature devices were checked and allwere within the specified limit of + 2¼C from eachother.

Note that the temperature loggers recorded diff e r-ent actual clock times. The loggers were not syn-chronized for this study, neither were they set to localtime. Each one was set for a different time zone.

C ompar isons B etween Data C ollected byT her mocouples and by W ir eless L ogger s

The thermocouples used are type T, copper-con-stantan thermocouples. The quality of wire and con-struction can significantly affect the accuracy of thethermocouples. The thermocouples used in thesetests are EllabÕs sealed thermocouples with a stain-less steel tip. The Ellab Tracksense logger sensor isa thermister made of a Silicon chip. Each logger andsensor has a separate ID number, and is factory cal-ibrated at five points in the range of -40 to 140¼C.The accuracy of the Ellab thermocouples and theEllab Tracksense sensors is +/-0.2¼C.

Figure 11

R es ults of One-Minute Open Door Tes t

4 5 . 0

4 0 . 0

3 5 . 0

3 0 . 0

2 5 . 0

2 0 . 007:58 08:08 08:18 08:28

S etting


TC 6 Bottom Back LeftTC 7 Bottom Back RightTC 8 Bottom CenterTC 9 Bottom Front LeftTC 10 Bottom Front Right

Figure 12

R es ults of 24-Hour L oadedC hamber Temperature Mapping

T hermoc ouples4 0 . 0

3 0 . 0

2 0 . 0

1 0 . 0

0 . 008:32 13:17 18:02 22:47 27:32

S etting


TC 6 Bottom Back LeftTC 7 Bottom Back RightTC 8 Bottom CenterTC 9 Bottom Left Fr o n tTC 10 Bottom Front Right


Can these data collection systems be used inter-changeably? Fi g u re 14 shows a summary of 10 hours ofdata from both the empty chamber 24-hour test and thefully loaded incubator test for both the wireless andthermocouple studies. The thermocouple data were col-lected on a real time system, EVAL, and the wireless

data were collected using EllabÕs Tracksense system.This summary demonstrates that both systems

generated comparable results. The differences in val-ues are well within the accuracy of both the thermo-couples and the thermisters, which is +/-0.2¼C.

When complementing thermocouples with wire-less loggers or using wireless loggers in place of ther-mocouples, the issue of real time versus historicaldata collection must be addressed. Thermocouples areconnected to real time data loggers, i.e., the data aredisplayed as collected. The wireless system is histor-ical, i.e., the data are downloaded and displayed at theconclusion of the test. Since the data cannot be seen,preliminary tests might need to be conducted to deter-mine the start time on a test, such as the 24-hour fullyloaded incubator, because the temperature of the incu-bator might drop during loading.

With a wireless system, there are no wires to gettangled and assembly can proceed quickly. The Ellabwireless data loggers are more stable and sealed, andneed less frequent calibration than thermocouples.Thermocouples are frequently not sealed, and there-fore subject to corrosion and degradation that willa ffect the calibration. It must be also kept in mindthat not all thermocouples and wireless data loggersare as accurate as the sensors used in this study.

Summary of Deviations:The following are the deviations that occurred dur-

ing the execution of this validation. All deviations from

Figure 13

R es ults of 24-Hour L oadedC hamber Temperature Mapping

Wireles s Trac ks ens e4 0 . 0

3 0 . 0

2 0 . 0

1 0 . 0

0 . 009:50 14:35 19:20 24:05 28:50

S etting

LC 1 L # 20022 S # 6422LC 2 L # 20753 S # 5757LC 3 L # 20770 S # 5747LC 4 L # 20764 S # 5770LC 5 L # 20804 S # 5766

LC 6 L # 20717 S # 5309LC 7 L # 20713 S # 5219LC 8 L # 20703 S # 4521LC 9 L # 11542 S # 5679LC 10 L # 11537 S # 4553

Figure 14

Data C ollection C omparis on B etween Thermocouples and Wireles s Dataloge rsA ll Values are in Degrees C entigrade

Type of Data F ile T i m e M i n i mu m M a x i mu m Av e r age Av e r age Delta T Av e r ageTe s t N a m e / S y s t e m I n t e rva l for all for all of Minimu m of Maximum ( R a n ge of all

(10 M i n i mu m M a x i mu m Va l u e s Va l u e s f ro m Va l u e sH o u rs ) Va l u e s Va l u e s Av e r age )

Empty Eval1.dt 6:00:00- 36.3 37.4 36.5 37.1 0.3 36.8Chamber 4/EVAL 16:00:00

Track1.dt 6:00:00- 36.3 37.4 36.7 37.1 0.2 36.84/Tracksense 16:00:00

Loaded Eval 22.dt 12:00:00- 35.5 36.9 35.9 36.3 0.3 36.1Chamber 4 22:00:00

Track2.dt 12:00:00- 35.4 36.8 35.9 36.3 0.5 36.24/Tracksense


the original protocol were justified and approved.There was no reference available for the Kaye

dry bath. Equipment was sent out to the manufactur-er for routine calibration. The internal bath referencewas used for all calibrations of the dry bath per-formed for this validation.

The protocol indicated that the chamber should beallowed to be at temperature range for at least 30minutes prior to conducting the five-minute openeddoor test. Based on OQ data, it was shown that theincubator is capable of maintaining the temperaturewithin the range for extended periods; therefore wait-ing 30 minutes would not have made a diff e r e n c e .

A 15-minute Opened Door Test was described onstep 15 of the PQ protocol. This was changed to a one-minute Opened Door Test, as typically incubator doorsare opened for not more than a couple of minutes. T h enew test length was considered to be reflective of areal situation.

The final post calibration of the thermocouples hadto be repeated because there was not enough data col-lected to confirm the high temperature calibration at40¼C. The EVA L Datalogger collects and displaysdata every two seconds, but the program was set tosave data every two minutes, and the system was shutdown before the final data were stored. Therefore, thecalibration was repeated at Star Services, Hayward,California, using a Kaye Liquid bath at two tempera-tures, 30¼ and 40¼C to confirm that the thermocoupleswere within specifications.

C onclusionsIQ

It is concluded that the unit was installed proper-ly. All necessary components were found to be pre-sent, and all the required SOPs were found to be inplace. The utilities (power) supplied to the unit, asper testing, were found to meet the requirements.

OQAll test results met the protocol acceptance crite-

ria. The unit is capable of maintaining the targettemperature.

PQAll test results met the protocol acceptance crite-

ria. Based on data obtained from the opened doortests and power failure, it can be concluded that nor-

mal laboratory practices are acceptable, and thatextending the incubation time for the same length oftime of the power failure is an acceptable solution.Note that time should be calculated from the timethe incubator reaches the temperature range (see rec-ommendations).

C onclusion

The incubator was tested and verified to operateproperly according to the manufacturer and protocolrequirements. This unit is therefore considered vali-dated.

RecommendationsIn order to have enough data collected, one should

consider running the temperature mappings with asafety factor of six hours, that is, for a 24-hour run,conduct a 30-hour mapping study, especially if wire-less sensors will be used.

The validation presented here was completed inthree days of continuous work. Scheduling and exe-cuting the work in this manner is taxing and compli-cated. At times, one will be working very early orvery late hours. Careful pre-scheduling is highly rec-ommended. Consider adding extra time to the sched-ule for unforeseen situations (example: chamber maynot get to temperature in the time you have predict-e d ) .

Older incubators that do not have a digital temper-ature display can benefit from having one installed.Digital temperature displays are available; they havea Real Time Datalogger (RTD) which is placed in theincubator either through a port (if available) orthrough the top vent.

Microbiologists should consider that after open-ing the incubator doors, the equipment loses heat,causing a decrease in temperature, which typicallyfalls outside the testsÕtemperature range. Based onthis, incubation times should be recorded from thetime the incubator is at temperature range, not fromthe time samples are placed in the incubator.

Caution must be exercised when reading temper-ature from an external chart recorder. Data from thisvalidation clearly showed that chart recorders areslow in capturing accurate temperature. o


A bout the Author sL a u ra Va l d e s - M o ra serves as Technical S ervices Dir-ector, acting as P rincipal C onsultant and NationalS p e a ker on US P Microbiology Updates and relatedtopics at E lite MicroS ource C orporation, a R esourceC enter for P harmaceutical and B iotechnology M i c r o-b i o l o g y. S he received a B. S . d e gree in Biology from theU n i versity of P uerto R ico in 1982, and an M.S . d e gr e ein Microbiology from North C arolina S tate University in1 9 8 6 .M s . Va l d e s - M o ra was a Director at AAI P h a rm a ,was fo rm e rly in charge of production of bacteri a lendospores at AMS CO, and has been the P residentof the P harmaceutical Microbiology F orum (P MF )s ince 1994. Ms. Valdes-Mora can be reached byphone at 850-763-5453, by fax at 850-913-9735, or bye-mail at E MS ource@ aol.com.

Pamela Hardt-E nglish, is P res ident of PhF S pecial-i s t s. S he has M.S . d e grees in Food S cience andA gri c u l t u ral E ngineering from the University of C alifo r-nia (Davis ) and a B. A . in C omputer S cience from theUnivers ity of C alifornia (B erkeley). For the last 23years at P hF S pecialists and FMC C orp o ration, Ms.Hardt-E nglish has served as a recognized F DA andU S DA process authori t y, instituted HAC C P progra m s,conducted thermal process ing studies , and valida-tions of autoclave s, incubators, and other chambers.S he has des igned and taught numerous food pro-cess ing courses. M s. Hardt-E nglish can be reached

by phone at 408-275-0161, by fax at 408-280-0979,or by email at phfspec@ pacbell.net.

Suggested R eadingThe following publications were consulted during the preparation of theprotocol, execution of the work, and preparation of the final report.

¥ Cloud, P.A., ÒValidating a Laboratory Incubator,Ó B i o p h a r m30,pp. 39-42. November (1997).

¥ Phil Cloud, Pharmaceutical Equipment Validation: T h eUltimate Qualification Guidebook (Interpharm Press, BuffaloGrove, IL1998).

¥ Cloud, P., ÒHow to Develop and Manage Qualification Proto-cols for FDACompliance.Ó (Interpharm Press, Buffalo Grove,IL 1999).

R efer ences1. Institute of Validation Te c h n o l o g y. Journal of Va l i d a t i o n

Technology. Vol. 8 No. 1, November 2001. pp. 63-72.

IQ: Installation QualificationLC: Wireless LoggersOQ: Operational QualificationPQ: Performance QualificationRT D : Real Time DataloggerS O P : Standard Operating ProcedureT C : T h e r m o c o u p l eUPS: Uninterrupted Power Supply TSA: Tryptic Soy AgarTSB: Tryptic Soy Broth

A r ticle A cr onym L isting

Documents

Validation of a Laboratory I ncubator U sing Wireless and Cabled