YSI TruLab pH 1110 - Manual (Page 19)

TruLab pH 1110 pH value
ba76155e01 03/2014
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Stability criteria (AutoRead )
The minimum duration until a measured value is assessed as stable is the
monitored time interval. The actual duration is mostly longer.
5.1.2 Measuring the temperature
For reproducible pH measurements, it is essential to measure the temperature
of the test sample.
You have the following options to measure the temperature:
• Automatic measurement of the temperature with the temperature sensor
(NTC30 or Pt1000) integrated in the sensor.
• Measurement with an external temperature sensor.
• Manual determination and input of the temperature.
The measuring instrument recognizes whether a suitable sensor is connected
and automatically switches on the temperature measurement.
Which type of temperature measurement is active is indicated by the tempera-
ture display and the [TP] status indicator:
If you wish to measure (or calibrate) without temperature sensor, proceed as
follows:
1. Measure the current temperature of the test sample.
2. Set the temperature value with <><>.
5.2 Calibration
5.2.1 Why calibrate?
When a pH electrode is operated, its zero point (asymmetry) and slope change
with the course of time. As a result, an inexact measured value is displayed.
Measured parameter Time interval Stability in the time interval
pH value 15 seconds ∆ : Better than 0.01 pH
Temperature 15 seconds ∆ : Better than 0.5 °C
Temperature
sensor
Resolution
of the temp.
display
Status
indicator Temp. measurement
yes 0.1 °C [TP] Automatic with temperature
sensor
- 1 °C - Manual