Fluke 5686, User Manual

5686

Users Guide

4

Verifying Probe Accuracy

Before using your probe, verify that its behavior has not changed significantly from the most 

recent calibration (as can sometimes occur from mechanical shock during shipping, for example). 

To verify your probe, check the probe at the Triple Point of Water (TPW) (0.01 °C) or in a well-

constructed ice bath, by following these steps:

1. 

Connect the probe to a calibrated readout and verify that the probe’s coefficients have been 

correctly entered into the readout.

2. Properly prepare a TPW cell or ice bath. Contact Fluke Calibration for assistance. A TPW cell 

is preferred. Ice baths should use distilled water and crushed ice in a Dewar flask or thermos 

bottle. The ratio of ice-to-water should be such that the mixture is firm after prepared.

3. Set your readout to read in ohms rather than temperature. Place your probe in the TPW or ice 

bath and allow it to stabilize. (Remember a TPW is at 0.01 °C and an ice bath is at 0 °C.)

4. If using a TPW cell, compare the resistance value on your readout with the resistance value 

at TPW given on the probe’s certificate. If using an ice bath, compare the resistance value on 

your readout with the resistance indicated on the certificate for 0 °C. (You may have to use 

the probe’s temperature versus resistance table and interpolate to get the probe’s calibrated 

resistance value at 0 °C.)

5. 

Considering the probe’s uncertainty specification, determine whether or not it is within 

tolerance of the data on its most recent certificate of calibration. If it is, it may be placed in 

service. If not, double-check the probe coefficients in the readout. If they are correct, contact 

Fluke Calibration.

Fluke Calibration recommends that a probe be periodically checked against a standard such as 

a TPW cell (or well-constructed ice bath if an ITS-90 fixed-point standard is not available). The 

verification interval depends on how the probe is handled, how and how much it is used, and your 

documented experience with it. Your probe should also be checked any time you suspect it may 

have received mechanical shock or whenever its accuracy appears suspect. 

How to Contact Fluke

To contact Fluke, call one of the following telephone numbers:

• Technical Support USA: 1-800-44-FLUKE (1-800-443-5853)
• Calibration/Repair USA: 1-888-99-FLUKE (1-888-993-5853)
• Canada: 1-800-36-FLUKE (1-800-363-5853)
• Europe: +31 402-675-200
• Japan: +81-3-3434-0181
• Singapore: +65-738-5655
• Anywhere in the world: +1-425-446-5500

Or, visit Fluke’s website at 

www.fluke.com

.

To register your product, visit 

http://register.fluke.com

.

To see, print, or download the latest manual supplement, visit

http://us.fluke.com/usen/support/manuals

.