Hach Polymetron pH/ORP Manual Del Usuario página 10

Option Description
Temperature For pH sensors only—adds a temperature-dependent correction to the measured value:
compensation
• Nernst—Linear compensation (0.1984 mV/°C)
• Ultrapure water—Compensation according to the ultrapure water curve
• Matrix 1 temperature compensation—Compensation according to the sulphate curve
• Matrix 2 temperature compensation—Compensation according to the
• Matrix 3 temperature compensation—Compensation according to the
• Matrix 4 temperature compensation—Compensation according to the phosphate curve
• User defined—Set the value of the linear slope.
Note: The above standards are only valid up to a maximum temperature of 50 °C.
Data logger Sets the time interval for sensor and temperature measurement storage in the data log—5,
interval 30 seconds, 1, 2, 5, 10, 15 (default), 30, 60 minutes.
Reset Sets the Settings menu to the factory default settings and resets the counters. All sensor
configuration to information is lost.
defaults
4.3 Calibrate the sensor
Fluid pressure hazard. Removal of a sensor from a pressurized vessel can be dangerous. Reduce
the process pressure to below 7.25 psi (50 kPa) before removal. If this is not possible, use extreme
caution. Refer to the documentation supplied with the mounting hardware for more information.
Chemical exposure hazard. Obey laboratory safety procedures and wear all of the personal protective
equipment appropriate to the chemicals that are handled. Refer to the current safety data sheets
(MSDS/SDS) for safety protocols.
Chemical exposure hazard. Dispose of chemicals and wastes in accordance with local, regional and
national regulations.
4.3.1 About sensor calibration
Calibration adjusts the sensor reading to match the value of one or more reference solutions. The
sensor characteristics slowly shift over time and cause the sensor to lose accuracy. The sensor must
be calibrated regularly to maintain accuracy. The calibration frequency varies with the application and
is best determined by experience.
A temperature element is used to provide pH readings that are automatically adjusted to 25 °C for
temperature changes that affect the active and reference electrode. This adjustment can be manually
set by the customer if the process temperature is constant.
During calibration, data is not sent to the datalog. Thus, the datalog can have areas where the data is
intermittent.
10 English
(4.48 mg/L sulphate corresponds to a pH of 4.0 at 25 °C)
ammoniac/hydrazine curve (0.272 mg/L ammoniac + 20 μg/L hydrazine corresponds to a
pH of 9.0 at 25 °C)
ammoniac/morpholine/hydrazine curve (1.832 mg/L ammoniac + 10 mg/L morpholine
+ 50 μg/L hydrazine corresponds to a pH of 9.0 at 25 °C)
(3 mg/L phosphates + 0.3 mg/L ammoniac)
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