ClearResultsAccuracy You Can Count On

Eric LinkLabtronX

I. Accuracy vsprecision

A digital alarm clock assures precision…but not accuracy

Accuracy Is…

Getting close to the bullseye

Precision is…

Gettingthe same results

When is it close enough?

II. Standards vs Readability

What is an Acre?

8 Furlongs Or 80 chains Or 320 Rods

1 Furlong long by1 Chain wide (4 Rods)

LENGTH OF A MILE?

Or 660 x 66 feet

Or 5280 feet

An Inch, A Foot, and A Yard

The Metrics of water

1 cubic cm of water =

1mL =

1g @ 25C

@ 1hpa

(Or 1mbar/22.92inhg)

@sea level

How do you report? Standard must be

more accurate than normal reported reading

Can not report more information than you have

Do not report Precision

Sensor +/-2.2C

Meter Resolution +/-0.1C

Meter Accuracy +/-0.1% + 0.7C

Each degree of Ambient Temperature above 28C or below 18c add 0.01% + 0.03C

Benchtop Turbidimeter

TL2300Tungsten

TU5200650nm

Range 0-4000NTU 0-40NTU

Resolution 0.001NTU 0.0001NTU

Repeatability 1% or 0.01NTU

1% or 0.002NTU

Accuracy 2% + 0.01NTU

2% + 0.01NTU

Readability

Precision

III. Being Proactive

In 1492 Columbus Sailed the Ocean Blue

He landed in the

Bahamas!

He proposed to sail west from the Canary Islands in hopes to find Japan and the riches of the East Indies.

Steven Callahan in 1982

In January , Steven Callahan set sail from the Canary Islands to solo the Columbus voyage

Steven Callahan in 1982• 6 days later, in the middle of the Atlantic Ocean, the boat sank

• He was left with a 5 foot life raft, 3 pounds of food, 8 pints of water, a solar still, and a makeshift spear

• 6 days later, in the middle of the Atlantic Ocean, the boat sank

• He was left with a 5 foot life raft, 3 pounds of food, 8 pints of water, a solar still, and a makeshift spear

Adrift : 76 Days Lost at Sea• He had to get food and fresh water and contend with the sun and

sharks

• 43 days later his raft sprung a leak that he could not patch

• He kept the boat afloat manually 33 more days, until his rescue

• Adrift on the currents, he traveled over miles

• He had to get food and fresh water and contend with the sun and sharks

• 43 days later his raft sprung a leak that he could not patch

• He had to get food and fresh water and contend with the sun and sharks

• 43 days later his raft sprung a leak that he could not patch

If you do nothing you WILL get somewhere (it may be miles)

If you do something you WILL get closer to where you want to go

Being reactive…dealing withthe day to day problems,is just surviving

Instead,decide where you want to goand chart a course

Where are you now?

IV. As FoundvsAs Left

The Basics of Navigation

He may have landed in Trinidad instead

of the Bahamas

If Columbus would have steered 270° 0

90

180

270 225

270

240

We know that accuracy and reliability

of lab equipmentdrifts overtime

Temperature Change

MoistureCorrosive Gasesand Chemicals

DustDirtInsects

StainedScratchedLenses & Glassware

Mechanical Parts

Consumable Parts

Vibration

Electrical Problems

A calibration and maintenance programMakes course correctionsBefore you drift too farFrom where you want to be

Clean, Calibrate, and Perform Periodic Maintenance

AS FOUND readingsWhere you were may not beWhere you wanted to be

AS FOUND

AS LEFT

DRIFT

The Difference betweenAS FOUND and AS LEFTEquals the DRIFT

DRIFT can help determineThe frequency of calibrationFor reliable and accurate readings

LabtronX Calibration RecommendationsTwice per year: All critical and reporting equipment

Frequent AS FOUND failures: may require additional calibration or investigation into the cause of the drift.

For systems using continuous turbidity monitoring, Chapter 109.301(1)(i)(B) requires at a minimum,calibration with an EPA-approved primary standard shall be conducted at least quarterly.

Verification should be done regularly to ensure accuracy

V. How do you know?

How do you know?I see the reported number but…

You did the proper test but…

You calibrated the meter but…

You used standards but…

Paperwork

Diploma of ‘How you know’

Unique ID

Equipment and Standards

Make/Model

Type

Serial Number

Nominal Value

Stated Value

Units

(Calculated)

AS FOUND

Meter Reading

Units

Must not damage standard

AS LEFT

Meter Reading

Units

Even without calibration

Pass/Fail

Agreed Standard deviation

Uncertainty caused by test method or standard

Correction Factor

Add or Subtract

Units

Not Deviation

Standard Documentation

Certificate with ID

Origin Date

Replacement Date

Last Verified

Test Method and/or equipment

conditions and uncertainty

Questions?

LabtronX800-830-2554