Revised 10/96 1
SPECIFICATION FOR KE-25
1. Specifications
1.1 Shape and Dimensions
The accompanying technical drawing (No. 88MD-109C--
see attachment) illustrates the fundamental design of the
oxygen sensor.
1.2 Characteristics
During normal operating mode, the sensor's output voltage
will range from 11.0 to 15.0mV under the following
standard conditions:
a) standard atmospheric pressure
b) temperature at 25˚C ± 1˚C
c) relative humidity at 60% ± 5%
1.3 Characteristic Data (typical values--see attachment)
Fig. 1: Oxygen concentration versus output voltage
characteristics
Fig. 2: Temperature versus output voltage characteristics
Fig. 3: Linearity of output voltage under accel. life test
Fig. 4: Long term stability of output voltage at room
temperature
1.4 Life Span
The life span of the sensor is defined as the elapsed time
period until the output voltage of the sensor falls to 70% or
less than the initial output voltage of the sensor. These
specifications apply under the following conditions:
a) standard atmospheric pressure
b) temperature of 25˚C ± 1˚C
c) relative humidity of 60% ± 5%
The life span of the sensor can be expressed by the
following equation:
Life span = oxygen concentration level (%) x operational hours (h)
(at constant temperature of 20˚
±
1˚C)
1.5 Storage and Operating Temperature
Storage temperature should be between -20˚C and +60˚C.
Operating temperature should be between 5˚C and 40˚C.
This corresponds to the effective range of the internal
temperature compensation circuit.
2. Handling Instructions
1) Do not expose the sensor to a temperature outside the
range between -20˚C and +60˚C.
2) Whether in use or in storage, keep the sensor either
horizontal or in a vertical position with the tip of the sensor
(where the hexagonal nut is locked into place) pointing
downwards only. This will prevent output signal fluctu-
ations which could be caused if the cathode were to dry out.
3) Prevent condensation on the sensing element.
4) Do not subject the sensor to excessive shock or vibration.
5) The sensor must be connected to equipment which has
an input impedance of 1000K ohms or higher.
6) The equipment to which the sensor is connected should
not generate a counter-electromotive force, i.e. it must
NOT charge the sensor.
7) Do not attempt to disassemble or repair the sensor.
3. Testing Procedures Prior to Shipment
KE-25 sensors are tested and passed by using the test
procedures as shown in the attached Table 89T-027B.
4. Warranty
Figaro warrants that KE sensors, when used under normal
conditions, will be free from defects in material and
workmanship for a period of one (1) year from date of
shipment. At its discretion, Figaro will repair or replace
any sensor which is found to be defective in materials or
workmanship while subjected to normal use and service
during this warranty period. The company shall not be
obliged to repair or replace any units found to be defective
due to damage, unreasonable use, or which have been
opened or otherwise physically altered. Sensors shall be
warranted to meet the following conditions for a period of
one year after the date of purchase from Figaro:
1) Va Test : 7.7mV ~ 15.0mV (KE-25)
2) Accuracy Test : (Va - V0) / (V100 - V0) = 0.21 ± 0.02
3) Vibration Test (directional alignment) : the sensor is
rotated 270˚ once per second for 10 seconds, during
which time Vair is recorded. From the original value,
output voltage observed in this test should within be
±0.5mV for KE-25.
Revised 10/96 2
SPECIFICATION FOR KE-25
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Sensor output (mV)
Temperature (˚C)
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Oxygen concentration (%)
Fig. 1 - Oxygen concentration vs. output voltage
characteristics of KE-25 (typical values)
Fig. 2 - Temperature vs. output voltage characteristics
of KE-25 (typical values)
Fig. 3 - Linearity of KE-25 output voltage under
accelerated life test (typical values)
Fig. 4 - Long term stability of KE-25 output voltage at
room temperature (typical values)
Table 89T-027B
Testing procedure for KE-25
Temperature = 25˚C
Relative Humidity - 60%
Relative Humidity - 60%
Accelerated life test conditions:
room temp. and 100% O2 conc.