Endress+Hauser OUSAF44, Руководство по эксплуатации

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Commissioning OUSAF44
20 Hauser
7 Commissioning
7.1 Function check
Prior to initial commissioning, ensure that:
• The sensor is correctly installed
• The electrical connection is correct
7.2 Calibrating/adjusting the sensor
Measuring points consisting of a photometer sensor, flow assembly (if provided) and a
transmitter are adjusted at the factory. Normally adjustment is not required when
commissioning for the first time.
If an adjustment is desired nevertheless, you have the following adjustment options:
• Adjustment with calibration standards
• Use of Easycal
7.2.1 Calibration/adjustment with standard solutions
Use solutions with a known absorbance (at the sensor wavelength) for the calibration/
adjustment.
L
WARNING
Potassium dichromate is toxic, flammable, carcinogenic and has mutagenic effects!
Can cause cancer, genetic defectives, affect fertility, harm the unborn child and intensify fires.
Potentially life-threatening if inhaled, toxic if swallowed, harmful if it comes into contact with
skin. Causes severe skin burns and severe eye damage!
‣
When working with potassium dichromate, always wear protective gloves and protective
goggles.
‣
Seek special advice before use.
‣
Follow all of the instructions on the manufacturer's safety data sheet.
Use calibration solutions that are suitable for the measuring task. Examples of solutions which
are commonly used include:
• Potassium dichromate, K
2
Cr
2
O
7
A solution of 182 ml 0.1N K
2
Cr
2
O
7
, diluted to one liter, has an absorbance of approx. 10 OD
at 280 nm. By diluting the solution, you can produce a series of calibration solutions which
you can use to adjust the measuring point.
• D-tryptophan
A protein which is also frequently used for optical calibration. A solution with a
concentration of 100 ppm has an absorbance of around 2.6 OD at 280 nm.
AU = OD*OPL[cm]
AU ... absorbance units, OD ... optical density, OPL .... optical path length
Producing a D-tryptophan parent solution
1. Dissolve 1 g D-tryptophan in a beaker containing 200 ml deionized water by heating (at
30 °C (86 °F)) and stirring (magnetic stirrer).