NIST/LC 

 

Information Technology:

NIST/Library of Congress (LoC) Optical 

Disc Longevity Testing Procedure 

NIST Special Publication 500-263 
NIST/LC 

Information Technology:

NIST/Library of Congress (LoC) Optical Media 

Longevity Study 

Information Access Division 

Information Technology Laboratory 

National Institute of Standards and Technology 

Gaithersburg, MD 20890-8950 

November 2005

U.S. Department of Commerce 

Carlos M. Gutierrez, Secretary 

Technology Administration 

Michelle O’Neill, Under Secretary of Commerce for Technology (Acting) 

National Institute of Standards and Technology 

William Jeffrey, Director 

NIST Special Publication 500-263
NIST/LC 

Reports on Information Technology 

 The Information Technology Laboratory (ITL) at the National Institute of Standards and Technology 

(NIST) stimulates U.S. economic growth and industrial competitiveness through technical leadership and 

collaborative research in critical infrastructure technology, including tests, test methods, reference data, and 

forward-looking standards, to advance the development and productive use of information technology. To 

overcome barriers to usability, scalability, interoperability, and security in information systems and networks, 

ITL programs focus on a broad range of networking, security, and advanced information technologies, as well 

as the mathematical, statistical, and computational sciences. This Special Publication 500-series reports on 

ITL’s research in tests and test methods for information technology, and its collaborative activities with 

industry, government, and academic organizations. 

Certain commercial entities, equipment, or materials may be identified in this document in order 

to describe an experimental procedure or concept adequately. Such identification is not intended 

to imply recommendation or endorsement by the National Institute of Standards and 

Technology, nor is it intended to imply that the entities, materials, or equipment are necessarily 

the best available for the purpose.

 

National Institute of Standards and Technology 

Special Publication 500-263 

Natl. Inst. Stand. Technol. 

Spec. Publ. 500-263 

23 pages (November 2005) 

CODEN: NSPUE2 

U.S. GOVERNMENT PRINTING OFFICE 

WASHINGTON: 2003

For sale by the Superintendent of Documents, U.S. Government Printing Office 

Internet: bookstore.gpo.gov — Phone: (202) 512-1800 — Fax: (202) 512-2250 

Mail: Stop SSOP, Washington, DC 20402-0001
NIST/LC 

Preface 

The Information Access Division (IAD) of the Information Technology Laboratory (ITL) at the 

National Institute of Standards and Technology (NIST), in collaboration with the Preservation 

Research and Testing division at the Library Of Congress (LoC) has begun a collaboration to test 

the longevity of recordable optical media including DVD-R, DVD+R, DVD-RW, DVD+RW, 

CD-R. The details of this collaboration are presented in this report. 

About the Library of Congress 

The Library of Congress is the nation's oldest federal cultural institution and serves as the 

research arm of Congress. It is also the largest library in the world, with more than 130 million 

items on approximately 530 miles of bookshelves. The collections include more than 29 million 

books and other printed materials, 2.7 million recordings, 12 million photographs, 4.8 million 

maps, and 58 million manuscripts. 

Preservation Research and Testing Division of the Library of Congress conducts scientific 

research to advance the preservation of the Library’s collections by extending their useful life as 

long as possible. Besides traditional book and manuscript materials, these collections include a 

variety of other media, including photographs, motion picture film, magnetic tape, and digital 

optical media such as CDs and DVDs. This division is also responsible for establishing 

specifications, acceptable practices, and testing protocols for all materials used for the 

conservation and/or storage of the Library’s permanent collections, as well as for specifying 

acceptable storage conditions, conservation practices and treatment processes that may have a 

direct or indirect impact on the longevity of the collections. 

About NIST 

Founded in 1901, NIST is a non-regulatory federal agency within the U.S. Commerce 

Department's Technology Administration. NIST's mission is to develop and promote 

measurement, standards, and technology to enhance productivity, facilitate trade, and improve 

the quality of life. NIST carries out its mission in four cooperative programs, the NIST 

Laboratories, conducting research that advances the nation's technology infrastructure and is 

needed by U.S. industry to continually improve products and services, the Baldrige National 

Quality Program, the Manufacturing Extension Partnership, and the Advanced Technology 

Program. 

NIST has an operating budget of about $858 million and operates in two locations: Gaithersburg, 

Md., (headquarters—234-hectare/578-acre campus) and Boulder, Colo., (84-hectare/208-acre 

campus). NIST employs about 3,000 scientists, engineers, technicians, and support and 

administrative personnel. About 1,800 NIST associates complement the staff. In addition, NIST 

partners with 1,400 manufacturing specialists and staff at affiliated centers around the country. 

The NIST/LoC Project Team: 

Jian Zheng (NIST (contractor), Lead Scientist), 

Oliver Slattery, Fred Byers, Arthur Klepchukov, Anna Nhan (NIST), 

Chandru Shahani, Michele Youket, Elmer Eusman (LoC). 
NIST/LC 

Acknowledgements: 

The authors would like to thank members of NISTs Information Access Division (IAD) and the 

LoCs Preservation Research and Testing Division (PRTD) who supported, helped with or 

participated in this project. 
NIST/LC 

1 Introduction 

The preservation of digital information has become a critical issue for many organizations, not 

least the libraries and archives of the US Government. According to the National Digital 

Information Infrastructure and Preservation Program (NDIIPP), which is administered by the 

LoC, information is being produced in greater quantities and with greater frequency than at any 

time in history. Furthermore, according to the NDDIIP, electronic media, especially the Internet, 

make it possible for almost anyone to become a "publisher." The program asks how will society 

preserve this information and make it available to future generations? Optical media has become 

the medium of choice for digital storage in many government agencies as well as many 

organizations within the private sector 

In June 2004, the Information Access Division of the National Institute of Standards and 

Technology (NIST) and the Preservation Directorate at the Library of Congress (LoC) agreed to 

perform a detailed investigation of the longevity of recordable Compact Disc (CD) and Digital 

Versatile Disc (DVD) media. This report outlines the procedural details of that investigation for 

estimating the life expectancy of information stored in CD-R, DVD-R and DVD+R, as well as 

DVD-RW and DVD+RW discs. The test procedure uses accelerated aging techniques and 

statistical analysis to estimate the life expectancy (LE) of current recordable DVD and CD 

media. This report also includes details of a ‘shelf-life’ test of recordable CD and DVD media, 

where blank media are aged artificially and their recording properties examined as the media is 

aged. 

Only the effects of temperature and relative humidity on the media are considered. The 

standardized life expectancy estimated using this model is defined for discs maintained at 25 oC 

and 50 % RH, but can be applied to give an estimate of the life expectancy at any moderate 

storage conditions. Discs exposed to more severe conditions of temperature and humidity are 

expected to experience a shorter life. The test plan does not attempt to model degradation due to 

exposure to light, corrosive gases, contaminants, or mishandling, nor does it account for 

variations in the playback subsystem. Furthermore, the compatibility of the recorder and the 

media will have a critical effect on the LE of media, including very stable media since error rates 

immediately after recording will impact the time before failure. For this study, great care was 

taken to ensure compatibility between the recorder and the media, thus ensuring low initial error 

rates. 

The ISO standard, ISO 18927:2002 (Imaging materials – Recordable compact disc system -- 

Method for estimating the life expectancy based on the effects of temperature and relative 

humidity, first edition), was used as a basis for the aging of the media and the analysis of data in 

this study, and thus some of the content of this paper will be familiar to those familiar with the 

ISO 18927:2002 standard. However, significant adaptations were required to ensure that suitable 

error rates and data points were obtained for recordable media. Initial testing, carried out in 2004 

and 2005, indicated that the stress conditions and durations described in ISO 18927:2002 

(minimum of 500 hours per aging cycle at increased temperature and humidity conditions) may 

be too harsh, with the result that very high error rates were obtained after just one aging period. 

An approach whereby the incubation length for each aging cycle could be altered, depending on 

the error trends, was adopted. 
NIST/LC 

The joint NIST/LoC optical media longevity test plan started in 2004 and it is expected that this 

investigation will be completed in 2006, after which results and analysis will be disseminated in 

a suitable publication, within the guidelines and legal restrictions agreed by NIST and the LoC. 
NIST/LC 

2 Technical Background 

Recordable optical disc media contains an organic dye layer whose transparency can be altered 

either to absorb the energy from a laser beam or to allow the beam to pass through to a reflective 

layer behind the dye [1,2,3]. The nature of this organic dye is such that when the internal 

energies of its molecules reach a particular threshold, an irreversible chemical reaction occurs, 

and the dye layer loses its transparency. This property allows a high-energy beam to ‘write’ data 

by burning ‘pits’, in the form of dark marks, to the disc during recording. A low powered laser 

reads the data by either passing through the transparent dye layer (without causing any molecular 

change) to the reflective layer or by being absorbed by the nontransparent marks in the dye. 

Due to the organic nature of the dye, degradation and breakdown of the transparent portion of 

dye layer will occur over a long period of time as a natural process. This process, which has its 

roots in chemical kinetics, can take several years in normal environment conditions [4]. Higher 

temperatures and humidity will accelerate this process by increasing the thermal and kinetic 

energies of the dye molecules. 

The effect of these processes can be modeled using various techniques including the Eyring 

model, which has a theoretical basis in chemistry and quantum mechanics and can be used to 

model acceleration when many stresses are involved. For this study, the Eyring equation will be 

used to model the effect of two stresses, temperature and relative humidity, on the rate of a 

reaction or degradation, which can be related to the time-to-failure of the optical disc.

The Eyring model has found broad application and shall be the model for estimating life 

expectancies of Recordable DVD systems. The equation 

a H kT B C T RH t AT e e / ( / )

50

∆ + =

where 

t50 is the time to 50 % media failure; 

A is the pre-exponential time constant; 

Ta is the pre-exponential temperature factor; 

∆H is the activation energy per molecule; 

k is Boltzmann's constant (1,38 × 10-23 J/K); 

T is the temperature, K; 

B, C is the RH exponential constants; 

RH is the relative humidity, %; 

was derived from the laws of thermodynamics and, in this form, can readily be seen to handle 

easily the two critical stresses of temperature and RH. For the temperature range used in this test, 

it is common practice to set a and C to zero [5]. 

The Eyring model equation then reduces to 

H kT B RH t Ae e / ( )

50

∆ =
NIST/LC 

3 Definitions 

DVD-R: 

Stands for Digital Versatile Disc – Recordable. A format of DVD which uses dye sublimation 

recording technology, and conforms with ISO/IEC DIS 23912:2005 Information technology - 80 

mm (1.46 Gbytes per side) and 120 mm (4.70 Gbytes per side) DVD Recordable Disk (DVD-R).

On DVD-R, data can be written to once and read many times. 

DVD+R: 

Stands for Digital Versatile Disc + Recordable. A format of a recordable DVD which uses dye 

sublimation recording technology, and conforms with ISO/IEC 17344:2005: Information 

technology -- Data interchange on 120 mm and 80 mm Optical Disk using +R format -- 

Capacity: 4.7 and 1.46 Gbytes per side. On DVD+R, data can be written to once and read many 

times. 

DVD-RW: 

Stands for DVD-ReWritable. A format of a re-writable DVD disc, which uses phase change 

recording technology, and conforms with ISO/IEC 17342:2004: Information technology -- 80 

mm (1.46 Gbytes per side) and 120 mm (4.70 Gbytes per side) DVD re-recordable disk (DVDRW). On DVD-RW, data can be written to several hundred times and read many times. 

DVD+RW: 

Stands for DVD+ReWritable. A format of a re-writable DVD disc, which uses phase change 

recording technology, and conforms with ISO/IEC 17341:2005: Information technology -- Data 

interchange on 120 mm and 80 mm optical disk using +RW format -- Capacity: 4.70 Gbytes and 

1.46 Gbytes per side. On DVD+RW, data can be written to several hundred times and read many 

times. 

CD-R: 

Stands for Compact Disc – Recordable. An extension of the CD format allowing data to be 

recorded once on a disc by using dye sublimation technology. Defined by part II of the Orange 

Book standard. Orange Book is the set of specifications created by Philips and Sony to define the 

optical signal characteristics, physical arrangement, writing methods and testing conditions for 

CD-R (Orange Book Part II) and CD-RW (Orange Book Part III) discs. 

Specimen: 

An individual disc as used in this aging study. 

Group: 

A collection of specimens that are aged under the same accelerated aging condition. 

Stress: 

A condition of elevated temperature and relative humidity used to accelerate the aging process 

for optical media in this study. 
NIST/LC 

ECC: 

Stands for Error Correction Code, additional information added to data to allow errors to be 

detected and possibly corrected. 

BLER: 

Stands for BLock Error Rate, a measure of the average number of raw channel errors when 

reading or writing CD type media. BLER is a measure of the number of data blocks per second 

that contain detectable errors at the input of the C1 decoder. 

E32: 

Stands for Error 32. In a CD system, there are two stages or levels of error correction codec. 

Each stage of the codec can correct two bad symbols in a block. The first number in an "E" error 

always references the number of errors and the second number always references the codec level. 

For example, the error type E11 means one bad symbol was corrected in the first stage (C1) or 

level 1; E21 means two bad symbols were corrected in the C1 stage; E31 means that there were 

three or more bad symbols at the C1 stage. This block is uncorrectable at the C1 stage, and is 

passed to the C2 stage. E12 means one bad symbol was corrected in the C2 stage and E22 means 

two bad symbols were corrected in the C2 stage. E32 means that there were three or more bad 

symbols in one block at the C2 stage. This error is not correctable. 

PI and PO: 

Stands for Parity Inner and Parity Outer. Reed-Solomon Product Code (RS-PC) is a method of 

error correction employing a number (usually two) of groups of Reed-Solomon parity bytes 

computed from rows, columns, or diagonals of a rectangular data array. DVD uses two-group 

method of RS-PC for error correction. The redundant codes of rows and columns are called 

Parity of the Inner code (PI) and of the Outer code (PO) respectively. DVD discs correct small 

read errors using PI, that operates on rows, and corrects large read errors using PO, that operates 

on columns of the data array. 

PIE: 

Stands for Parity Inner Error. The number of error corrections made on incoming rows of data in 

the first pass of the decoder using the inner parity correction code. A row of an ECC Block that 

has at least 1 byte in error constitutes a PI error. PIE is measured over 8 ECC blocks. In any 8 

consecutive ECC Blocks the total number of PI errors before correction shall not exceed 280, 

also called as PI Sum 8. 

POE: 

Stands for Parity Outer Errors. Parity outer fails. The decoder was unable to correct the data 

using the outer parity codes. It is measured over 1 ECC block.

Incubation Cycle: 

A complete single incubation cycle includes the initial ramping to stress conditions, the 

maintenance at that stress condition and ramping back to ambient conditions. This is described in 

section 4 of this paper. 
NIST/LC 

Life expectancy: 

The length of time (usually measured in years), up to which, a disc is expected to provide access 

to data stored on it with no uncorrectable errors. For this study, and in general for optical media, 

it is the length of time before the level of correctable errors is such that the onset of uncorrectable 

errors is imminent. For CD type media, this means the length of time before BLER reaches 220 

and for DVD type media, this means the length of time before PIE reaches 280. 

Shelf life: 

The length of time, up to which, a blank disc is expected to be suitable for recording. 

EOL: 

Stands for End of Life. The state of the disc when the level of correctable errors is such that the 

onset of uncorrectable errors is imminent. For CD type media, this means when BLER reaches 

220 and for DVD type media, this means when PIE reaches 280. Also may be used to describe 

the point at which uncorrectable errors actually occur. 

Time to failure: 

From the point of view of this study, the time to failure is the time taken, in hours, for a 

specimen to reach the EOL. 
NIST/LC 

4 Procedure 

4.1 Procedural overview: 

A sampling of one hundred recorded discs is divided into six groups (Table 2). Each group of 

discs is exposed to one of six stresses, which are combinations of temperature and relative 

humidity as described in section 4.3. After each period of incubation, each disc shall have its 

BLER (in the case of CD type media) or inner parity (PI) errors (in the case of DVD type media) 

measured (Fig. 1). Data collected at each test point for each individual disc will be used to 

determine a time to failure (usually measured in hours) for that disc. The times to failure for 

discs at each stress are fitted to a log-normal distribution to determine a mean time to failure for 

that stress. The resulting six mean times to failure are regressed against temperature and relative 

humidity according to an Eyring acceleration model. This model is then used to estimate the 

distribution of lifetimes at a preferred usage condition. 

Fig. 1: Example of a testing and incubation timeline for the six stress conditions. 

4.2 Test method: 

The process of accelerated aging requires that discs in each stress condition be ramped from 

ambient conditions to that stress condition in an environmental chamber, maintained at that stress 

condition for a particular period of time and then ramped back to ambient conditions. This 

incubation cycle will occur a minimum of four times and possibly more during the course of 

testing. The ramp duration and conditions must be chosen to allow sufficient equilibration of 

absorbed moisture within the substrate. Large departures from equilibrium conditions can result 

in the formation of liquid water droplets inside the substrate or at its interface with the recording 

layer. Gradients in the water concentration through the thickness of the substrate must also be 

limited. These gradients drive expansion gradients, which can cause significant disc curvature. 

In order to minimize the effects of moisture concentration gradients in large chambers, the ramp 

profile outlined in Table 1[6] is used. The ramp durations specified ensure minimal stress in the 

specimens. A complete incubation cycle, including the ramp and aging stages, are portrayed 

graphically for one of the stress conditions in Fig. 2. 

Time

= Testing Point

= Additional Testing

Stress 

Severity 

Incubation Cycle
NIST/LC 

Table 1 — Temperature and RH ramp profile1

Process step Temperature (oC) RH ( % RH) Duration (hours) 

start at Tamb at RHamb --- 

T, RH ramp to Tinc to RHint 1.5 ± 0.5 

RH ramp at Tinc to RHinc 1.5 ± 0.5 

incubation at Tinc at RHinc see Table 2 

RH ramp at Tinc to RHint 1.5 ± 0.5 

equilibration at Tinc at RHint see Table 2 

T, RH ramp to Tamb to RHamb 1.5 ± 0.5 

end at Tamb at RHamb --- 

Fig. 2: Graphically portrays one incubation cycle at 80 oC and 85 % RH.

A system independent of the chamber control system shall be used to monitor the temperature 

and the relative humidity conditions in the test chamber during the stress test for independent 

verification of every chamber conditions. 

4.3 Test conditions: 

 The stress conditions used in this study are shown in Fig. 3. They include the five stress 

conditions specified in the ISO 18927:2002 standard, with an additional stress at 70 °C and 70 % 

RH. Table 2 specifies the temperatures, the relative humidity (RH), the initial incubation cycle 

durations, the minimum number of incubation cycles and the sample distributions for each stress 

condition. If necessary, more incubation cycles may be added or the duration of the incubation 

may be increased to determine the time to failure of the media at any specific stress. A separate 

group of specimens is used for each stress condition. This procedure constitutes a constant-stress 

test plan. All temperature stress points have an allowed range ±2 oC and all relative humidity 

stress points have an allowed range of ±3 %RH. 

 

1 Tamb and RHamb are room ambient temperature and RH, Tinc and RHinc are the stress incubation temperature and 

RH, RHint is the intermediate RH that, at Tinc, supports the same equilibrium moisture sorption in polycarbonate as 

that supported at Tamb and RHamb (see Table 2). 

= Temperature 

= Relative Humidity

Temp 

(oC) 

RH 

(%) 

Time (hr)
NIST/LC 

 

Fig. 3: Stress conditions of acceleration aging. 

Table 2 - Summary of stress conditions 

Group 

number 

Number of 

specimens 

Test stress 

(Tinc, RHinc) 

Initial incubation 

cycle duration 

Minimum # 

of cycles 

Intermediate 

RH(RHint) 

Equilibration 

duration 

1 10 80 oC, 85 % 100 h 4 31 % 6 h 

2 10 80 oC, 70 % 100 h 4 31 % 5 h 

3 15 80 oC, 55 % 100 h 4 31 % 4 h 

4 15 70 oC, 85 % 150 h 4 33 % 8 h 

5 20 70 oC, 70 % 150 h 4 35 % 7 h 

6 30 60 oC, 85 % 200 h 4 36 % 11 h 

The intermediate RH (RHint) in Table 2 is calculated assuming a 25 oC and 50 % RH ambient. If 

the ambient conditions are different, the intermediate RH to be used is calculated using the 

equation: 

(0.24 0.0037 ) (0.24 0.0037 ) * ( ) RHint = + Tamb + Tinc RHamb

where 

Tamb is the ambient temperature in units of oC; 

Tinc is the incubation temperature in units of oC; 

RHamb is the ambient RH.

The stress conditions tabulated in Table 2 offer a sufficient combination of temperature and RH 

to satisfy the mathematical requirements of the Eyring model to demonstrate linearity of either 

natural logarithm (ln) of the max BLER (ln(max BLER)) versus time in the case of CD type 

media, or ln(max PI errors) versus time in the case of DVD type media, and produce a 

satisfactory confidence level to make the desired conclusions. 

4.4 Test specimens: 

Test specimens shall be nominally identical with regard to substrate groove structure, layer 

structure, coating composition, recording capacity, and age prior to test initiation. Media should 

be chosen from different lots and production lines in order to be representative of normal process 

variations. All discs shall be maintained within the manufacturer's shipping and at ambient 

Temperature

Relative 

Humidity 
NIST/LC 

storage conditions prior to recording. Table 3 and Table 4 describe the recordable CD and DVD 

media chosen as test specimens for this study. 

Each Brand discs will be recorded disc-at-once with a single session recording. In other words, 

the disc shall be recorded such that the entire disc is written to in one pass without turning off the 

laser. Any CD type disc that, after recording, meets the Yellow Book (Philips-Sony Compact 

Disc Read Only Memory System Description) specification (also described in the ISO/IEC 

10149 or EMCA-130 standards) can be included in the remainder of this study. Likewise, any 

DVD type media that, after recording, satisfies the DVD specification (described in ISO/IEC 

16448:2002 or ECMA-267, third edition, April 2001 standards) can be included in the remainder 

of this study. Any specimen that exhibited unusual error rates immediately after recording is not 

included, and care must be taken to ensure that initial error rates were consistent through out the 

full diameter of the test specimen. 

4.4.1 For CD-R discs: 

Since the emergence of CD-R technology, a number of different dye types have been used as the 

recording layer, including Cyanine, Phthalocyanine, and Metallized Azo, or their hybrids [7]. 

However, due to current conditions in the dye market, a single dye type has become the most 

popular in CD-R media and is based on the Phthalocyanine dye. Several popular brands were 

tested in this study as shown in Table 3 below. Due to limitations with the CD analyzer, it is not 

possible to include CD-RW type media in this study. See appendix I for more detailed 

information on these media. 

Table 3 — CD-R media included in this study2 

Product 

Brand 

Type Bar code Manufacturer name 

NOT FOR CD-R NOT FOR NOT FOR 

PUBLIC CD-R PUBLIC PUBLIC 

DISCLOSURE CD-R DISCLOSURE DISCLOSURE 

CD-R 

NOT FOR CD-R NOT FOR NOT FOR 

PUBLIC CD-R PUBLIC PUBLIC 

DISCLOSURE CD-R DISCLOSURE DISCLOSURE 

4.4.2 For recordable and rewritable DVD discs: 

There are several different types of recordable DVD available, including DVD-R for general, 

DVD-R for Authoring, DVD+R, DVD-RW, DVD+RW, DVD-RAM and more recently dual 

layer DVD. Not all types are compatible with each other but could potentially be used in archival 

applications. In this study, we will examine DVD-R for general, DVD-RW, DVD+R and 

DVD+RW. Table 4 shows the media included in this study with more details in Appendix 1. 

Table 4 — DVD media included in this study 

Product 

Brand 

Type Bar code Manufacturer name 

NOT FOR DVD-R NOT FOR NOT FOR 

PUBLIC DVD-R PUBLIC PUBLIC 

DISCLOSURE DVD-R DISCLOSURE DISCLOSURE 

 

2

 CD analyzers used in this study are not capable of testing CD-RW type media. 
NIST/LC 

 DVD-R 

NOT FOR DVD-R NOT FOR NOT FOR 

PUBLIC DVD+R PUBLIC PUBLIC 

DISCLOSURE DVD+R DISCLOSURE DISCLOSURE 

DVD+R 

NOT FOR DVD+R NOT FOR NOT FOR 

PUBLIC DVD+R PUBLIC PUBLIC 

DISCLOSURE DVD-RW DISCLOSURE DISCLOSURE 

DVD-RW 

NOT FOR DVD+RW NOT FOR NOT FOR 

PUBLIC DVD+RW PUBLIC PUBLIC 

DISCLOSURE DVD+RW DISCLOSURE DISCLOSURE 

4.4.3 For CD-ROM and DVD-ROM discs: 

For comparison, 100 CD-ROM discs and DVD-ROM discs divided in to six groups are included 

and will be subjected to the same stresses and test conditions as the recordable discs. All CDROM discs are provided by LoC, while NIST provides all DVD-R, DVD+R, DVD-ROM and 

CD-R media. 

 

4.4.4 For the shelf time test:

Media included in the shelf life study are the same brands of media used in the aging studies. 

Discs from each brand are split into six groups for each stress condition. After every aging 

period, one blank disc from each brand will be recorded and tested to determine its useful shelf 

life. Attempts to achieve one successful recording will continue until all the media is used up.

4.5 Analyses of the discs: 

BLER (block error rate) for CD-R 

The ratio of erroneous blocks to total blocks measured at the input of the first (C1) decoder 

(before any error correction is applied) as defined in ISO/IEC 60908. The maximum BLER is 

measured as the biggest number of BLER at anywhere on a disc. 

Inner Parity Errors for DVD 

Maximum of PI errors are less than 280 as defined by the DVD specification, or ISO/IEC 

16448:2002 or ecma-267, third edition, April 2001. 

4.6 Measurements and collecting data: 

This study uses the measured maximum BLER for recordable CD and CD-ROM and the 

measured maximum inner parity (PI) errors for recordable DVD as a high-level estimate of the 

quality of the media at the time of measurement. The purpose of measuring BLER and PI errors 

is to establish a practical estimation of a compatible system's ability to read the recorded data 

without uncorrectable errors occurring. 

However, the correlation between actual loss of information and the measured maximum BLER 

and PIE actually depends on several factors including the playback system as well as the media 

quality. A BLER of 220 and the PI errors of 280 are conservative levels chosen by the recordable 

CD and DVD specifications as a predictor of the onset of uncorrectable errors and thereby end of 

life. 
NIST/LC 

4.6.1 Media recording and initial data: 

There are many formats and speeds of discs (for example, 4X, 8X, 16X...) in the market and yet 

no unified standard for the drive write strategy. Therefore each recorder drive manufacturer 

develops their own drive to satisfy to the write/read requirements of recordable CD and DVD 

discs. As such, there is no guarantee that the recorder used to burn a disc is fully compatible with 

that disc. This can, and often does, lead to very high error rates immediately after recording the 

disc, which in turn can make aging analysis very difficult. It is therefore important to ensure that 

initial error rates are low by ensuring that the recording drive and the media are as compatible as 

possible[8,9]. 

To ensure recorder drive and media compatibility, four Disc Burning Stations (DBS) were built 

in the NIST laboratory with high-end computers and new recorder drives. Each drive must have 

the latest update to its firmware to ensure its best performance. 

To determine the recorder with the highest level of compatibility with each brand of media, a 

limited number of recordings will be made for each brand by each recorder in the four DBS. The 

test specimens will then be burned as needed by the most compatible recorder and initial error 

rates monitored to ensure that the recorder continues to operate correctly. 

For this study, media with a BLER (in the case of CD type media) below 40 and with PIE (in the 

case of DVD) below 100 are included. 

4.6.2 Disc Burning Stations: 

In an effort to ensure the integrity of the results, all disc burning station (DBS) computer 

configurations should be the same. For this investigation, each disc burning station (DBS) 

consists of a Pentium-4 processor workstation with the following specifications: 

Intel Pentium-4 Processor 3.6 GHz w/ 800mhz FSB, 

1GB DDR2-533 MHz dual channel RAM, 

Seagate 120 GB 7200 rpm SATA hard drive w/ 8 MB cache, 

Microsoft Windows XP Pro w/ doc and media.

All test specimens will be indexed so as to associate it with the particular DBS and DVD 

recorder drive used to record that brand (see appendix 1). The recording drives used in this study 

include the Sony DRU-510A, 700A, 800A, Pioneer DVR-A09, Plextor PX-716SA and NEC 

ND-2510A. The drive chosen for the particular brand of media will be the drive shown to be 

most compatible with that media. 

Each DBS will be equipped with Roxio Easy Media Creator 7, version 7.5.0.47 ENU. The same 

image will be recorded on DVD media at the most compatible speed. The same image will be 

recorded on all CD media also at the most compatible speed. 

4.6.3 Analyzer: 

 In order to monitor the change in the error rate during the aging, the discs are analyzed after 

each incubation cycle using optical disc analyzers. A CD analyzer capable of reading BLER (in 

the case of CD) and a DVD analyzer capable of reading PI error (in the case of DVD) are used. 
NIST/LC 

For testing DVD: CATS SA300 DVD-R/RW PRO and CATS DVD+R/RW PRO from Audio 

Development are used to analyze the DVD media in this study. These systems measure recorded 

and unrecorded DVD discs and include the Pulstec SDP-1000 optical drive. All relevant 

parameters including inner parity error (PIE), outer parity error (POE), jitter, asymmetry and 

more are measured using this system. 

For testing CD: CD CATS SA3 Advanced can measure all relevant parameters of CD discs. All 

measurements are performed according to optical disc industry standards. All relevant 

parameters including correctable BLER (including E11, E12, E21, and E22), uncorrectable E32 

errors, jitter, asymmetry and more are measured using this system. Unfortunately, this system is 

not capable of testing CD-RW type media, which is why CD-RW media is not included in this 

study. 

Continuous calibration of all testers must be performed to ensure the integrity of the results as 

testing is ongoing. Should the calibration test determine that the testers are not fully calibrated, 

the testers must be recalibrated and all testing performed since the testers were last shown to be 

calibrated must be repeated. 

4.6.4 Collecting data 

Test specimens are not analyzed in their entirety but analyzed at five test bands throughout the 

diameter of the test specimen. DVD test points are located at the following radii (in millimeters): 

24.00 to 25.20, 31.95 to 33.15, 39.90 to 41.10, 47.85 to 49.05, and 55.8 to 57.00, from the inside 

to the outside of the disc. CD-R test points are at the following times (in minutes:seconds): 

00:00 to 03:00, 19:00 to 22:00, 38:00 to 41:00, 57:00 to 60:00, 76:00 to 79:00. 

The same tester will be used for any particular test specimen through out the study and each 

specimen will be indexed to associate it with the analyzer used to analyze that specimen. 

4.7 Requirements of incubation condition: 

The temperature and relative humidity levels used in this study are chosen to ensure that there is 

no change of phase of the moisture within the environmental chamber over the test temperature 

range, and such that no condensation occurs on cooler sections of the chamber such as 

observation windows, cable ports, wiper handles, and so on. Any droplets caused by such 

condensation could damage the media and/or influence the error rates. Furthermore, the 

temperature of the testing environment must not be so high so as to cause any plastic 

deformation within the disc structure. 

Practical experience shows that 80 oC and 85 % RH is the upper limit for control within most 

accelerated test cells. Table 2 shows the complete stress conditions used in this study. 

Disc samples shall be uncovered and placed vertically within the chamber. Discs shall be aligned 

so that their surfaces are parallel to the chamber airflow. A space of at least 2 mm shall be 

maintained between discs. 
NIST/LC 

4.7.1 Environmental Chambers: 

A Parameter Generation and Control Inc (model: 9131-3119) 30 cubic feet environmental 

chamber is used to control precisely the temperature and relative humidity through various 

combination settings of temperatures (5 °C to 85 °C) and relative humidity (10 % to 95 %). The 

controlled accuracy is ± 0.2 °C for temperature and ±0.5 % for relative humidity. 

4.8 Incubation time requirements: 

Since there are six stress conditions to be implemented, the media from each brand will be split 

into six groups (see Table 2). Depending on the error rates observed as the testing progresses, 

one to three chambers would be required for this study. Based on initial incubation cycle 

durations and the number of media to be tested, all initial incubation cycle testing can be 

complete in the timeline shown in Fig. 4. The most severe stress (80 oC, 85 %) will be conducted 

first and tested after incubation to determine if the incubation durations should be increased and 

to what extent. In such a case where the incubation time is increased extensively, additional 

chambers can be used. Increasing the incubation durations should not increase the total duration 

of the study since the limiting factor is the number of analyzers available to test the large 

numbers of media. There are two analyzers available for testing DVD media and one available 

for testing CD media. 

Fig. 4: Initial incubation cycle testing timeline. 

4.9 Ten-step analysis outline for data: 

The following is a brief outline of the steps required to estimate the life expectancy of 

information stored in a Recordable DVD system as a function of temperature and RH, as taken 

from the ISO 18927:2002 standard for CD-R and applies to this study also. 

1) Determine the failure time for each specimen. 

2) Determine, for each stress, the median rank of each specimen, and plot median rank versus 

failure time on a log-normal graph. 

3) Verify that the plots for all stresses are reasonably parallel to one another. The log standard 

deviation for each stress may be calculated using standard techniques or estimated from 

straight lines drawn through the plots. 

4) Calculate the log mean for each stress. 

= Aging underway

= Testing underway

Stress 

Severity 

Time Schedule
NIST/LC 

5) Regress log mean, temperature, and RH for all stresses using the reduced Eyring equation. 

Calculate the estimated log mean for the standardized temperature and RH(25 oC and 50 % 

RH). 

6) Determine the acceleration factor for each stress. 

7) Normalize all the failure times by multiplying each failure time by the acceleration factor for 

its stress. 

8) Combine all normalized failure times and censored data into one data set. For this entire set, 

make one composite log-normal plot. 

9) Estimate the log mean and the log standard deviation at the usage conditions from this plot, or 

the combined data. 

10) Calculate confidence intervals for the survival function. 

5 Normative references 

• ISO 18927:2002 Imaging materials – Recordable compact disc systems – Method for 

estimating the life expectancy based on the effects of temperature and relative humidity, 

first edition 

• IEC 60908 (1999-02): Compact disc digital audio system. This document including 

amendments approximates the Philips-Sony Red Book 

• ISO/IEC 10149:1995, Read-Only 120 mm Optical Data Disks (CD-ROM) 

• EMCA130 2nd Edition - June 1996 Data interchange on read-only120 mm optical data 

disks(CD-ROM) 

• Orange Book, part B, -- Recordable Compact Disc System, November 1990 (SONY and 

Philips Corp.)

• ISO/IEC 16448:2002 Information technology -- 120 mm DVD -- Read-only disk

• ISO/IEC DIS 23912:2005 Information technology - 80 mm (1.46 Gbytes per side) and 

120 mm (4.70 Gbytes per side) DVD Recordable Disk (DVD-R)

• ISO/IEC 17344:2005: Information technology -- Data interchange on 120 mm and 80 

mm Optical Disk using +R format -- Capacity: 4.7 and 1.46 Gbytes per side

• ISO/IEC 17342:2004: Information technology -- 80 mm (1,46 Gbytes per side) and 120 

mm (4,70 Gbytes per side) DVD re-recordable disk (DVD-RW)

• ISO/IEC 17341:2005: Information technology -- Data interchange on 120 mm and 80 

mm optical disk using +RW format -- Capacity: 4,7 Gbytes and 1,46 Gbytes per side

• ECMA-267, 2001, 120 mm DVD - Read-Only Disk, 3rd edition 

• ECMA-337, DVD+RW - Rewritable Optical Disks, 4.7 GB 

• ECMA-338, DVD-RW - Rewritable Optical Disks, 4.7 GB 

• IEEE 101-1995, Guide for the statistical analysis of thermal life test data

6 Bibliography 

[1] Hamada, E, et al, Recording process of recordable compact disc, Optical Data Storage, 

D. B. Carlin and D. B. Kay, eds., Proc. SPIE 1663, 443–446, 1992. 

[2] Yokota, C, et al, Phthalocyanine CD-R for high-speed recording, Optical Data Storage, 

G. R. Knight, H. Ooki, and Y. Tyan, eds., SPIE Proc. 2514, 249–257, 1995 
NIST/LC 

[3] H. Bennett, Understanding CD-R and CD-RW, Optical Storage Technology 

Association, California, USA (2003). 

[4] Murray, W.P. Accelerated service life predictions of compact disks, ASTM STP 1202, 

p.263-271. American Society for Testing and Materials, 1994 

[5] Tobias, P.A. and Trindade, D.C. Applied Reliability. New York: Van Nostrand 

Reinhold, 1986 (2nd ed. 1995). 

[6] Wrobel, J.J., Ramp profiles for optical disc incubation, SPIE vol. 2338, optical data 

storage, p. 191-202, 1994 

[7] Oliver Slattery, et al, “Stability Comparison of Recordable Optical Discs—A Study of 

Error Rates in Harsh Conditions”, Journal of Research of the National Institute of 

Standards and Technology, Vol. 109, Number 5, September-October 2004 

[8] Slattery, O.T. DVD-ROM Drive Compatibility Test for DVD-R(General), DVD-RW, 

DVD+R, DVD+RW and DVD-RAM Discs (Phase1), NIST Special Publication 500-

254, October 2003 

[9] Slattery, O.T. DVD Drive Compatibility Test for DVD-R (General) and DVD+R Discs, 

including DVD Creation Plan (Phase2), NIST Special Publication 500-258, September 

2004

[10] Experimental Statistics, National Bureau of Standards Handbook 91. Washington, DC, 

US: National Institute of Science and Technology, 1963. 
NIST/LC 

Appendix I: 

Disc code system for the Life Expectancy test 

Jian Zheng @ July 26, 2005 

Where 

 A C, A, B, D, or E stands for CD-R, DVD-R, DVD+R, DVD-RW or DVD+RW 

discs respectively. 

 BB Brand of the media as below Table 

 nnn Series number 

 Gg g is the group number of the specimen 

 Xmm mm is the burning speed 

C the symbol of the burner, as shown in table below 

s the number of the Disc Burning Station (DBS). 

T the number of the tester. Tester 1 is AudioDev’s SA3 CD 

CATS MLH2100 for CD; Tester 2 is AudioDev’s SA300 

DVD CATS Pro DPEP 1486 for DVD+R/RW; and Tester 

3 is the DPER 1534 for DVD-R/RW. 

[Note] read out the disc information with Roxio DVDInfo Pro version 4.08 embedded in Roxio 

Easy Media Creator 7.5. 

All CD-R discs use Short Strategy for burning, meaning all discs use Phthalocyanine dye. 

Burner Company and model Serial number Firmware revision 

E Sony DRU-510A AE74DBFC BB►1.1 

F Sony DRU-510A AE74DBFC BB►1.1 

G Sony DRU-700A 2004052000038341 VY08 

H Pioneer DVR-A09 ECD015716UJ 1.17►1.57 

I Pioneer DVR-A09 ECD015528UJ 1.17►1.57 

J Plextor PX-716SA 124136 1.07►1.08 

K Plextor PX-716SA 124246 1.07►1.08 

L _NEC ND-2510A 

(MadDog MD-8XDVD9) 

46NGK89S211 2.05►2.F9 

M Sony DRU-800 

N Sony DRU-800 

Brand BB

NOT FOR ** 

PUBLIC ** 

DISCLOSURE ** 

 ** 

NOT FOR ** 

PUBLIC ** 

DISCLOSURE ** 

 ** 

Code Format: ABBnnnGgmmCst 

Burner, DBS and tester 

Group and Burning speed 

Series number

Category and brand 
NIST/LC 

Manufacturer and Brand Information Table for DVD Discs 

ABB Brand Type Order code Bar code Media code/Manufacturer ID 

(revision) 

 DVD-R discs 

A** 

A** NOT FOR NOT FOR NOT FOR NOT FOR 

A** PUBLIC PUBLIC PUBLIC PUBLIC 

A** DISCLOSURE DISCLOSURE DISCLOSURE DISCLOSURE 

A** 

 DVD+R discs 

B** 

B** NOT FOR NOT FOR NOT FOR NOT FOR 

B** PUBLIC PUBLIC PUBLIC PUBLIC 

B** DISCLOSURE DISCLOSURE DISCLOSURE DISCLOSURE 

B** 

 DVD-RW discs 

D** NOT FOR NOT FOR NOT FOR NOT FOR 

D** PUBLIC PUBLIC PUBLIC PUBLIC 

 DVD+RW discs 

E** NOT FOR NOT FOR NOT FOR NOT FOR 

E** PUBLIC PUBLIC PUBLIC PUBLIC 

E** DISCLOSURE DISCLOSURE DISCLOSURE DISCLOSURE 

 

Manufacturer and Brand Information Table for CD Discs

A** Brand Order 

code 

Bar code ATIP* Capacity** Manufacturer 

name 

LBA 

C** NOT FOR NOT FOR NOT FOR NOT FOR NOT FOR NOT FOR NOT FOR 

C** PUBLIC PUBLIC PUBLIC PUBLIC PUBLIC PUBLIC PUBLIC 

C** DISCLOS

URE 

DISCLOS

URE DISCLOSURE DISCLOSURE DISCLOSURE DISCLOSURE DISCLOSURE 

C** 

C** NOT FOR NOT FOR NOT FOR NOT FOR NOT FOR NOT FOR NOT FOR 

C** PUBLIC PUBLIC PUBLIC PUBLIC PUBLIC PUBLIC PUBLIC 

C** DISCLOS

URE 

DISCLOS

URE DISCLOSURE DISCLOSU

RE DISCLOSURE DISCLOSURE DISCLOS

URE 

* ATIP Start Time of Lead In (Media Code) **Free Capacity/ ATIP Last Possible Start Time of Lead Out