Hitachi OE700 Series, Operating Manual

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9 Maintenance
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50 Hitachi High-Tech Analytical Science
9.11 Measuring adapters
For measuring wire samples and tubes with a diameter of < 11 mm, the diameter of the
spark stand opening in the spark stand plate must be reduced in order to increase
measuring accuracy.
For this purpose, a boron nitride collimator and two different wire adapters are available.
•
The boron nitride collimator reduces the diameter of the spark stand opening from
10 mm to 5 mm.
• The wire adapters retain the wire on the spark stand plate.
• Using the adapters, you can measure samples with a diameter of < 3 mm with
sufficient precision.
• Generally, it is preferable to use the "face-on" adapter in order to achieve more
consistent measuring results and avoid surface effects.
Information
Even if the constant argon flow reduces the negative effects of an open spark stand
opening, it is indispensable to shield the measuring spot from ambient air for the precise
determination of carbon (C) and phosphorus (P).
A disadvantage of boron nitride is that the boron contained therein is also contained in
steel. During sparking, a contamination with boron can therefore not be excluded, and
a recognition of boron concentrations in steel of < 30 ppm cannot be guaranteed.
Risk of electric shock!
The boron nitride collimator is non-conductive. Small parts measured using the
collimator do not have earthing contact with the instrument, thus there is a risk of electric
shock!
•
Do not touch the sample during measurement!
• Should the hold-down device shift or any other inadvertent event occur during a
measurement, always switch off the excitation source before remedying the error.
Touch the boron nitride collimator carefully so that it does not break.
1. Place the adjustment aid (1, fig. 9-10) for the wire adapter onto the spark stand
plate and fix the adjustment aid using the knurled screw (2).
2. Insert the boron nitride collimator (3) into the spark stand opening.
Fig. 9-10 Adjustment air and boron nitride collimator (example)
3
1
2