Inspection Equipment Accuracy - Measuring the diameters of small holes

L

Liger

#1
I have a piece of inspection equipment we use for measuring the diameters of small holes (.017-.018") machined into a plate. The inspection equipment has a stated measurement accuracy of .00014". Our engineers want data reported to 6 figures. My position is the sixth figure they are requesting exceeds the capability of the machine and that it may get reported, but the accuracy of that 6th digit cannot be relied upon. Is my position correct?
 
Elsmar Forum Sponsor
M

msec0990

#2
I believe you're correct, because you only have five significant digits in this case. To add a sixth would create false precision. But since I don't deal with this often, I'd like to see what others have to say.
 

normzone

Trusted Information Resource
#3
I'm with [msec0990].

To my simple mind, if the device makes claims to about one and one half ten thousandths, then any info it gives you should be viewed as possibly plus or minus that amount.

So any number out in that fourth decimal place could possibly be out into the fifth decimal place, and the sixth decimal place is just there for entertainment purposes.
 
I

iamtroll

#5
Since the stated accuracy is not .00001", even the fifth place decimal is questionable. In reality, you should be doing a gage R&R to determine the actual accuracy for the characteristic you are interested in. I had the same problem recently with a customer that wanted a six place accuracy, we told them just because you can put five zeros and a number after the decimal place doesn't mean anyone can measure it. We use lasers to measure coating thickness and they only go to five places. And don't forget temperature variation, even if you had a device that could measure to six places you would have to keep the temperature in your measuring lab at around +-.1 degree F of variation or your size will change.
 
Thread starter Similar threads Forum Replies Date
M Accuracy of Inspection Equipment - How precise does the measurment device need to be? Inspection, Prints (Drawings), Testing, Sampling and Related Topics 3
B 4DINSPEC Inspection Equipment General Measurement Device and Calibration Topics 0
K First Article Inspection (FAI) - Equipment used - Dimensions vs. Go/No-Go ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 7
B 7.1.5.1.1 MSA for inline dimension vision inspection equipment IATF 16949 - Automotive Quality Systems Standard 5
M IATF 16949 Clause 7.1.5.1.1 - What are "inspection equipment systems"? IATF 16949 - Automotive Quality Systems Standard 4
A Quality Plan - Inspection method, equipment list for inspection of a Spur Gear Inspection, Prints (Drawings), Testing, Sampling and Related Topics 1
V Handling decomissioned line/equipment during 1st time product-based inspection US Food and Drug Administration (FDA) 1
C Gage R&R on In-Process Automated Inspection Equipment Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 13
S How to do Adjustments & Repairs on Common Inspection Equipment General Measurement Device and Calibration Topics 7
F Aged Inspection Equipment Software has no Audit Trail - Validation of Software Qualification and Validation (including 21 CFR Part 11) 5
J Inspection Equipment for Checking Serrated Steel Tubing Depths Inspection, Prints (Drawings), Testing, Sampling and Related Topics 2
J Calibrate before use required? Inspection Gages and Measurement Equipment ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 9
AnaMariaVR2 Laboratory Equipment Quality System - Calibration, Maintenance and Inspection Pharmaceuticals (21 CFR Part 210, 21 CFR Part 211 and related Regulations) 10
T CP: Is it feasible to define the inspection equipment as final function tester? APQP and PPAP 12
B Attribute MSA of Automatic Inspection Equipment Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 7
M Calibration Procedures for Inspection Equipment? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 12
D CSA Inspection - Process equipment shipped elsewhere to process product Various Other Specifications, Standards, and related Requirements 9
R Construction: Does new Inspection and Measurement Equipment require calibration? General Measurement Device and Calibration Topics 22
D Manufacturer' Service Provider - Calibration of inspection test equipment General Measurement Device and Calibration Topics 6
A Final Inspection - Calibrated M&TE (Measurement and Test Equipment)? Inspection, Prints (Drawings), Testing, Sampling and Related Topics 2
J Employee Owned Inspection Equipment Inspection, Prints (Drawings), Testing, Sampling and Related Topics 14
A Calibration of inspection, measuring and test equipment Inspection, Prints (Drawings), Testing, Sampling and Related Topics 12
A Method of Disposition on Damaged Inspection,Measuring Test Equipment Inspection, Prints (Drawings), Testing, Sampling and Related Topics 1
M 4.11 Control of Inspection Measurement and Test Equipment Inspection, Prints (Drawings), Testing, Sampling and Related Topics 3
J Incoming Inspection Records using Excel File ISO 13485:2016 - Medical Device Quality Management Systems 2
J Requirements as a Distributor for Incoming Inspection of Purchased Finished Medical Device Medical Device Related Regulations 0
J Action Not defined in procedure - NC - Incoming inspection AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 1
S Annual Inspection Layout - Based on Customer print ? IATF 16949 - Automotive Quality Systems Standard 8
I Overwhelmed with attribute MSA requirement for visual inspection IATF 16949 - Automotive Quality Systems Standard 8
K Visual Inspection Effectiveness Inspection, Prints (Drawings), Testing, Sampling and Related Topics 16
A Fabric roll inspection - What type of Control Chart to use? Inspection, Prints (Drawings), Testing, Sampling and Related Topics 2
B Industrial RX inspection of welds (Oil&Gas industry) Reliability Analysis - Predictions, Testing and Standards 0
C In-process inspection - Tooling and assembly lines for automotive companies AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 6
D FAA inspection at my repair station - Rating Check Federal Aviation Administration (FAA) Standards and Requirements 0
G Supplier delivered recent PPAP, should he deliver yearly layout inspection? IATF 16949 - Automotive Quality Systems Standard 4
R Inspection and Work order process Inspection, Prints (Drawings), Testing, Sampling and Related Topics 9
M Determining a tolerance value for Measuring devices in-house inspection General Measurement Device and Calibration Topics 12
P Need a programmer for QVI's VMS software for optical inspection machine Inspection, Prints (Drawings), Testing, Sampling and Related Topics 0
silentmonkey How to decide what characteristics need to be verified during incoming inspection? ISO 13485:2016 - Medical Device Quality Management Systems 5
Y What are different Special Inspection Level 1-4 and General spesification 1-3 ? AQL - Acceptable Quality Level 0
J Mechanical inspection techniques of close tolerance parts Inspection, Prints (Drawings), Testing, Sampling and Related Topics 4
T Help to Suggest name for a new certification and inspection company Coffee Break and Water Cooler Discussions 7
B GM GP-12 Exit Criteria - Additional Safe Launch Inspection - (Also see GM1927-28 ) Customer and Company Specific Requirements 2
S Process Inspection -Sub assembly process inspection sheet Lean in Manufacturing and Service Industries 3
C OEE and In-process Inspection Manufacturing and Related Processes 2
R AS9100 - 8.4.2 - Receiving Inspection Requirements AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 1
I Mother bobbin final inspection criteria Inspection, Prints (Drawings), Testing, Sampling and Related Topics 3
Marc Visual Inspection - Color Vision Coffee Break and Water Cooler Discussions 15
G Inspection Logs - Asked to remove an Inspection Sheet ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 4
Skooma Receiving Inspection - Boss trying to save money AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 7

Similar threads

Top Bottom