Agilent Technologies | 34420A | 34420A-04 - Keysight Technologies

34420A-04
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SUPERSEDES: NONE
34420A - Nano Volt/Micro Ohm Meter
Serial Numbers: US36000000 - US36001171
Inaccurate temperature readings
To Be Performed By: Agilent-Qualified Personnel
Parts Required:
P/N
Description
Quantity
34420-69211
Rebuilt 34420A Product (exchange unit)
1
Note:
The 34420A may be returned to factory for an update.
Situation:
THIS SERVICE NOTE ONLY APPLYS TO UNITS USED FOR
MEASURING TEMPERATURE.
When using certain temperature sensors and taking many temperature measurements that include certain temperature points, the 34420A will display a temperature that is 8, 4 or 2 degrees lower than the actual temperature for those key points. The locations of these points
are dependent on the type of temperature sensor being used and the temperature measuring
method employed.
Continued
DATE: Janurary 1999
ADMINISTRATIVE INFORMATION
SERVICE NOTE CLASSIFICATION:
MODIFICATION RECOMMENDED
ACTION
CATEGORY:
IMMEDIATELY
ON SPECIFIED FAILURE
AGREEABLE TIME
STANDARDS:
LOCATION
CATEGORY:
SERVICE
INVENTORY:
AVAILABILITY:
CUSTOMER INSTALLABLE
ON-SITE
SERVICE CENTER
PRODUCT'S SUPPORT LIFE
RETURN
USED
RETURN
SCRAP
PARTS:
SCRAP
SEE TEXT
SEE TEXT
AGILENT RESPONSIBLE UNTIL: January 2001
AUTHOR:
ENTITY: 0940
ADDITIONAL INFORMATION:
REM
LABOR
0.5 Hours
© 1999 AGILENT TECHNOLOGIES
PRINTED IN U.S.A.
1 of 3
Page 2
Service Note 34420A-04
Solution / Action:
These low readings are caused by a math error in the voltage to temperature conversion firmware
routines.
Units with firmware code 04-XX-XX or less have this defect.
Firmware code version may be determined by using the following front panel key sequences:
(Turn unit off and then on. )
Key Stroke
Display
Shift(Blue key), "<"
"<"
"<"
"<"
"V"
"<"
"V"
A:MEAS MENU
G:CAL MENU
F:I/O MENU
E:SYS MEMU
1:RDGS STORE
1:REVISION
REV ??-XX-XX
These measurement errors are limited to temperature measurements made with RTD’s and certain
thermocouple types.
Measurements made with thermistors and SPRT’s are not affected by this firmware defect.
If you are using thermocouple sensors in the external reference junction configuration, that is
where two thermocouples or more are involved in the measurement, we recommend that the unit
be updated or replaced.
List of temperature sensors affected by this defect when used in the single sensor configuration:
Temperature
Sensor Type
RTD’s
T thermocouple
N thermocouple
J thermocouple
E thermocouple
B thermocouple
Chance of seeing the
defect (per reading)
1 in 75000
1 in 27000
1 in 13000
1 in 28000
1 in 6500
1 in 174000
Affected temperature
range
above 620° C
above 209° C
above 122° C
above 774° C
above 57° C
above 1520° C
List of temperature sensors affected by this defect when used in the reference junction
configuration:
S thermocouple
R thermocouple
K thermocouple
T thermocouple
N thermocouple
J thermocouple
E thermocouple
B thermocouple
Service Note 34420A-04
Page 3
If the unit has 04-XX-XX or less firmware code then the unit can be replaced or updated. If
unit is still under the standard warranty, replacement is recommend. For units out of warranty,
updating the unit is preferred.
To have unit replaced:
For USA & Canada customers, call 1-800-258-5165 or contact your local Agilent Service Center to
arrange to have your instrument replaced.
For other customers, please contact your local Agilent Service Center.
To have unit updated:
If customer wishes to have his unit updated then unit must be returned to the factory. Processing
time for this upgrade will be less than one week plus shipping time. The unit should be shipped to
the address listed below with the instruction requesting this update ( reference this service note).
Include a "Ship to" address for returning the modified unit.
Instrument Repair Coordinator
MS DU402
Agilent Technologies
Loveland Site
815 14th Street S.W.
Loveland, CO 80537
USA
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