Newnes Sensor Technology Handbook 2005 Yyepg Lotb Part 16 potx

A P P E N D I X ALifetime Cost of Sensor Ownership Analyzing It, Calculating It Overview “There is nothing in the world that some man cannot make a little worse and sell a little cheaper

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A P P E N D I X A

Lifetime Cost of Sensor Ownership

Analyzing It, Calculating It

Overview

“There is nothing in the world that some man cannot make a little worse and sell a little cheaper, and he who considers price only is that man’s lawful prey.”

If your company purchases a PC, the initial purchase price may only be 10% of the total lifetime cost of the computer Installation, support, training, upgrades, and re- pairs usually dwarf the initial outlay.

Have you looked at the total cost of ownership for the sensors and transducers you are using? Do you look at these costs before making a specification?

Typical “Initial Cost” Purchase Analysis

When someone asks you how much did something “cost,” you typically state a figure based on what was shown on the quote, invoice, or receipt In the case of a transducer, this is often only the cost of the transducer and possibly an amount for shipping, taxes, and related transaction costs.

purchas-Installation Does the transducer design require you to make a special mounting

plate or is flexible mounting inherent in the product? How long does installation take? Can installation be performed by a lower-skilled employee or must a higher- skilled technician or engineer perform the task?

Cabling, Connectors, and Signal Conditioning Does the sensor require the

pur-chase of additional electrical cable, electrical connectors, signal conditioning, and related instrumentation?

Reliability What is the stated lifetime of the product? Does it have an MTBF

(mean time before failure) rating? Does the vendor have reliability statistics of the product being used in an environment similar to your own? Unscheduled downtime costs can be huge in factory automation, aviation, and capital-inten- sive applications.

Scheduled Down Time Is calibration or scheduled maintenance required? How will

this downtime affect your operations? Will alternate sensors need to be installed? Can this work be done during other maintenance periods?

Repairs Is the product repairable or is it discarded at the end of its lifetime? Are

there costs associated with its disposal? Can the repair be performed on site or must the item be returned to the manufacturer?

Calibrations Can calibrations be performed on site or is factory return required?

How often are calibrations required and what is the cost?

Usability Is the signal from the product easy to work with or does it require

special-ized power supplies, amplifiers, and related equipment that must be procured, installed, learned, and configured?

Lifetime Cost of Sensor Ownership

Lead Time Longer lead times require you to spend more time scheduling and may

require you to stock sensors to avoid stock out situations.

On-time Performance Does the sensor get delivered on time? If you planned for

receiving the item in 7 days but the shipment does not show up for 21 days, you will spend valuable time re-scheduling resources and nagging the vendor to get the product to you.

Environmental Rating Unintended uses can often make environmental protection an

important feature A misplaced cup of coffee or an inadvertent blow from a toed shoe can wreak havoc on your “office environment” sensor And increase your costs And if you plan to add environmental protection yourself, remember to add this cost to the solution’s total cost.

steel-Shipping It may not seem like much to pay a flat small fee for shipping But add that

flat small fee over spare parts, factory calibrations, repairs, and replacements and the amount can become substantial.

If shipping is based on weight and volume, look at the products you are ering specifying Are there any size or weight differences? Are there are tariff differences related to the products originating from different countries?

consid-Stocking Requirements Lead time, reliability, repairability, ontime shipping and

other factors influence the stocking (inventory) levels required for the transducer.

A rule of thumb is that annual inventory carrying costs are 25% with ranges from 18% to 75% Your carrying costs may be higher than 25% based on this analysis:

To reiterate, the above are annual carrying costs that will continue as long as you

hold the products in your inventory.

Warranty What is the length of warranty? What are the terms of the warranty? Are

extended warranties available? What are the warranty restrictions?

Training Are there extraordinary education or training requirements to use the sensor

and related instrumentation? Is calibration straightforward is a course required?

Documentation Are adequate user manuals and application notes available? Do

us-ers need to spend valuable time learning and documenting the product?

Customer Service Is customer service readily available? What are the hours of

op-eration? How responsive is customer service to your inquiries regarding pricing, shipping information, and repairs? Is Web site pricing and ordering available?

Technical Support Is technical support available 24/7/365? Are there fees

associ-ated with technical support? Is the information provided complete, accurate, and timely?

Still Not Convinced?

Do you believe total cost of ownership is not relevant in your application? Consider the experience of an airline who went with “an affordable” choice only to find out 15 months later that the transducers were surviving for only 12 months on average and needed to be replaced annually The replacement transducer selected did cost 20% more but was available off-the-shelf and was previously qualified for aircraft use There have been no failures with the replacement transducers and no replacements have been required after 36 months of continuous use.

The Bottom Line

To do an interactive comparison of sensor and transducer total lifetime costs, use the Total Cost of Ownership Calculator at http://spaceagecontrol.com/calctco.htm.

Conclusion

The selection of the proper sensor or transducer for a given application includes an evaluation of the costs of the sensor or transducer Initial purchase costs can be less than 20% of the product’s lifetime costs.

Only by considering the lifetime costs can you ensure you are specifying an optimum solution.

Appendix A

Lifetime Cost of Sensor Ownership

References and Resources:

1 For an analysis on downtime costs, see The Hidden Cost of Downtime

(Smart-Signal Corporation)

2 Richardson, Helen: Transportation & Distribution, “Control Your Costs Then Cut Them,” December 1995.

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2 What is IEEE 1451.2?

The first of these standards was IEEE 1451.2 The standard was designed to gain

a standard way to specify the device operation and calibration, a standard cal interface between the sensor and the communications device, and the ability to use standardized off-the-shelf components to build smart sensors IEEE 1451.2 had considerable challenges that ultimately led to virtually no adoption of it in practical applications

physi-3 What is IEEE 1451.4?

IEEE 1451.4 directs its attention to only the TEDS part of the sensor and signal conditioning system IEEE 1451.4 adopts a valuable approach by taking a much more simple approach to other smart sensor concepts by simply focusing on the self-identification aspects of a sensor IEEE1451.4 does this by specifying a table of self-identifying parameters that are stored in the sensor in the form of a TEDS (Trans- ducer Electronic Datasheet)

4 What is P1451.4?

The IEEE1451.4 committee have only published a draft specification All indications are that the standard will change slightly before it is published in its final format National Instruments and its sensor partners have decided not to wait for the final ver- sion and are suggesting that sensor vendors start producing sensors based on the draft specification The draft specification is defined as P1451.4 for (P)reliminary release,

to separate it from the eventual 1451.4 specification

Appendix B

5 What is TEDS?

TEDS is an acronym for Transducer Electronic Datasheet It is a table of parameters that identify the transducer and are held in the transducer on a EEprom for inter- rogation by external electronics The definition of the table is still not fully defined

by the IEEE committee so carries the designation IEEE P 1451.4 for preliminary Note: TEDS is the data contained on a sensor that is defined by IEEE1451.4 Honey- well Sensotec has for the last 8 years used the TEDS concept in its SIG CAL or SIG MOD This TEDS in the SIG CAL Plug and Play technology is defined by Honeywell Sensotec rather than the IEEE1451.4 standard

6 What data is carried in 1451.4 TEDS?

There are four areas of TEDS data One is the basic data that identifies the transducer The EXTENDED TEDS is where all the electrical and physical properties are stored The USER area is where a sensor user can store data regarding the sensors location, next calibration date etc The TEMPLATES section has yet to be fully defined by the IEEE1451.4 committee but will likely contain additional data that is distinct for each class of sensor and will be compiled by the manufacturer An example of this might

be the calibration curve for a ASTME74 load cell

Basic TEDS

Standard and Extended TEDS

User Area Templates

Manufacturer ID Sensotec Model Number 41 Serial Number 462992 Version Letter 53e Calibration Date April 22, 2002 Temperature effect on span 0.0045 Temperature effect on offset 0.0045 Min Operating Temperature -53 Max Operating Temperature 121 Response Time 0.0005 Min Electrical Output -2 Max Electrical Output +2 Sensitivity 1.998 Bridge Impedance 350 Excitation Nominal 10 Excitation Maximum 15 Excitation Minimum 3 Max Current Draw 30 Sensor Location 23 right dyno Calibration Due Date April 21, 2003 Special Calibration Date 12.3-0 175x-0.00

Wiring Code Wiring Code #15

Transducer Electronic Data Sheet

TEDS

Used

Active

lyUsed Passively

IEEE 1451.4 TEDSMakes table availablefor interrogation

Interrogates tableand sets instrument

up ready to goSensotecPlug Play and Calibrate

1010010100101010 1110111001011101

1010010100101010 1110111001011101

Smart Sensors and TEDS FAQS

7 What is the output of a TEDS sensor?

There are two types of TEDS sensor outputs: four wire outputs or two wire outputs/ two wire ICP outputs (Integrated Charge Pump) used on accelerometers In the case

of four wire systems the standard calls for two additional wires to carry the digital TEDS data On two wire systems the Digital TEDS data in digital format share the same wires as the analog signal

8 What is Plug and Play?

Plug and Play is the name adopted for the technology surrounding IEEE1451.4 Plug and Play, however, suggests that the user can plug the sensor into the signal condition- ing and everything is automatically configured and is ready to take measurements The IEEE1451.4 standard does not explicitly ensure that this is the case For example, the IEEE1451.4 specification does not, as yet, address the hardware connection by specifying a connector and wiring code nor does it address what to do with the TEDS data once the signal conditioning has read the information off the EEprom It is up to sensor manufacturers to use the dot 4 standard either passively or actively Honeywell Sensotec has chosen to use the IEEE1451.4 table actively and provides ‘Plug, Play and Calibrate’ of the sensor and signal conditioning system

Sensoranalog outputDigitalTEDS Data

1010010100101010 1110111001011101

Appendix B

9 Honeywell Sensotec ‘Sig Cal’ and IEEE 1451.4

The IEEE1451.4 standard was written around the same EErom as utilized by the eywell Sensotec ‘Sig Cal’ Conversion of a Sig Cal sensor to IEEE1451.4 requires

Hon-a softwHon-are chHon-ange only The IEEE 1451.4 defines Hon-a pHon-assive system only where the table of data that resides in the sensor ‘Sig Cal’ on the other hand uses a Honeywell Sensotec defined table of data and then uses that data to set up the SC2000 so that it is ready to run Sig Cal is true ‘Plug, Play and Calibrate’

A P P E N D I X C

Units and Conversions

Table of Basic and Derived SI Units

SOME DERIVED SI UNITS

Appendix C

SOME DERIVED SI UNITS (continued)

Units and Conversions

Conversion Factors

This table provides conversion factors to convert various units to their SI equivalents

Appendix C

(continued)

Units and Conversions

Electrical Units

A P P E N D I X D

Physical Constants

Appendix D

Physical Constants

Appendix D

Physical Constants

Appendix D

Physical Constants

Appendix D

A P P E N D I X E

Dielectric Constants

Dielectric Constants and Strengths

Values are relative dielectric constants (relative permittivities) As indicated by

er = 1.00000 for a vacuum, all values are relative to a vacuum

[Multiply by e0 = 8.8542 x 10-12 F/m (permittivity of free space) to obtain absolute permittivity.]

Substance Dielectric Constant k (relative) Dielectric Strength (V/mil) Max Temp (°F)

7400 4400

4.5 - 8.0

(continued)

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A P P E N D I X G

Engineering Material Properties

This table gives various engineering material properties listed alphabetically The units are SI.

Appendix G

(continued)

Engineering Material Properties

(continued)

Appendix G

(continued)

Engineering Material Properties

(continued)

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A P P E N D I X H

Emissions Resistivity

Table of Total Emissivity

The following tables are presented for use as a guide when making infrared ture measurements with the OMEGASCOPE® or other infrared pyrometers The total emissivity (ε) for metals, non-metals and common building materials are given.

tempera-Since the emissivity of a material will vary as a function of temperature and surface finish, the values in these tables should be used only as a guide for relative or delta measurements The exact emissivity of a material should be determined when abso- lute measurements are required.

Appendix H

Alloys

20-Ni, 24-CR, 55-FE, Oxid 392 (200) 90

20-Ni, 24-CR, 55-FE, Oxid 932 (500) 97

60-Ni , 12-CR, 28-FE, Oxid 518 (270) 89

60-Ni , 12-CR, 28-FE, Oxid 1040 (560) 82

Highly Polished Plate 440 (227) 04

Highly Polished Plate 1070 (577) 06

Bright Rolled Plate 338 (170) 04

Bright Rolled Plate 932 (500) 05

Alloy A3003, Oxidized 600 (316) 40

Alloy A3003, Oxidized 900 (482) 40

Burnished to Brown Colour 68 (20) 40

Cu-Zn, Brass Oxidized 392 (200) 61

Cu-Zn, Brass Oxidized 752 (400) 60

Cu-Zn, Brass Oxidized 1112 (600) 61

Molten 1000 (538) 15 Molten 1970 (1077) 16 Molten 2230 (1221) 13 Nickel Plated 100-500 (38-260) 37 Dow Metal 0.4-600 (–18-316) 15 Gold

Plate (.0001) Plate on 0005 Silver 200-750 (93-399) 11-.14 Plate on 0005 Nickel 200-750 (93-399) 07-.09 Polished 100-500 (38-260) 02 Polished 1000-2000 (538-1093) 03 Haynes Alloy C,

Oxidized 600-2000 (316-1093) 90-.96 Haynes Alloy 25,

Oxidized 600-2000 (316-1093) 86-.89 Haynes Alloy X,

Oxidized 600-2000 (316-1093) 85-.88 Inconel Sheet 1000 (538) 28 Inconel Sheet 1200 (649) 42 Inconel Sheet 1400 (760) 58 Inconel X, Polished 75 (24) 19 Inconel B, Polished 75 (24) 21 Iron

Oxidized 212 (100) 74 Oxidized 930 (499) 84 Oxidized 2190 (1199) 89 Unoxidized 212 (100) 05

Liquid 2760-3220 (1516-1771) 42-.45 Cast Iron

Oxidized 390 (199) 64 Oxidized 1110 (599) 78 Unoxidized 212 (100) 21 Strong Oxidation 40 (104) 95 Strong Oxidation 482 (250) 95 Liquid 2795 (1535) 29 Wrought Iron

Polished 100 (38) 28 Lead

Polished 100-500 (38-260) 06-.08

Oxidized 100 (38) 43 Oxidized at 1100°F 100 (38) 63 Gray Oxidized 100 (38) 28 Magnesium 100-500 (38-260) 07-.13 Magnesium Oxide1880-3140 (1027-1727) 16-.20

Monel, Ni-Cu Oxid at 1110°F1110 (599) 46 Nickel

Polished 100 (38) 05 Oxidized 100-500 (38-260) 31-.46 Unoxidized 77 (25) 05 Unoxidized 212 (100) 06 Unoxidized 932 (500) 12 Unoxidized 1832 (1000) 19 Electrolytic 100 (38) 04 Electrolytic 500 (260) 06 Electrolytic 1000 (538) 10 Electrolytic 2000 (1093) 16 Nickel Oxide 1000-2000 (538-1093) 59-.86 Palladium Plate (.00005

on 0005 silver) 200-750 (93-399) 16-.17 Platinum 100 (38) 05

Plate (0.0005 on Ni) 200-700 (93-371) 06-.07 Polished 100 (38) 01

" 2000 (1093) 03 Steel

Cold Rolled 200 (93) 75-.85 Ground Sheet 1720-2010 (938-1099) 55-.61 Polished Sheet 100 (38) 07

Mild Steel, Polished 75 (24) 10 Mild Steel, Smooth 75 (24) 12 Mild Steel,

Liquid 2910-3270 (1599-1793) 28 Steel, Unoxidized 212 (100) 08 Steel, Oxidized 77 (25) 80 Steel Alloys

Type 301, Polished 75 (24) 27 Type 301, Polished 450 (232) 57 Type 301, Polished 1740 (949) 55 Type 303, Oxidized 600-2000 (316-1093) 74-.87 Type 310, Rolled 1500-2100 (816-1149) 56-.81 Type 316, Polished 75 (24) 28 Type 316, Polished 450 (232) 57 Type 316, Polished 1740 (949) 66 Type 321 200-800 (93-427) 27-.32 Type 321 Polished 300-1500 (149-815) 18-.49 Type 321 w/BK Oxide 200-800 (93-427) 66-.76 Type 347, Oxidized 600-2000 (316-1093) 87-.91 Type 350 200-800 (93-427) 18-.27 Type 350 Polished 300-1800 (149-982) 11-.35 Type 446, Polished 300-1500 (149-815) 15-.37 Type 17-7 PH 200-600 (93-316) 44-.51 Type 17-7 PH

Polished 300-1500 (149-815) 09-.16 Type C1020,

Oxidized 600-2000 (316-1093) 87-.91 Type PH-15-7 MO 300-1200 (149-649) 07-.19 Stellite, Polished 68 (20) 18 Tantalum, Unoxidized 1340 (727) 14

" 2000 (1093) 19

" 3600 (1982) 26

" 5306 (2930) 30 Tin, Unoxidized 77 (25) 04