ARJAY ENGINEERING HYDROSENSE 2410, Руководство пользователя

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HYDROSENSE HS2410 Revision 5.0 P a g e 25 | 27
10.0 SAMPLE PREPARATION (F
OR
C
ALIBRATION OR
T
ESTING
)
Testing may be preformed in a number of ways.
1. An unknown concentration may be used to provide a response test. This does not verify the
accuracy or calibration of the instrument but does confirm that it will respond and alarm to a high
concentration condition.
2. An unknown sample with a concentration of contaminant can be sent to a lab for analysis.
3. A concentration blend may be made using the stream fluid and a known concentration of
contaminant.
If a sample concentration is to be made, the contaminant must be made to emulsify in the stream fluid.
This can be difficult, as the concentrate often will not break down enough to provide an even
distribution in the low PPM range.
For example, a sample of 50 PPM (parts per million) is equal to 1 oz in 20,000 oz. (125 gallons). To use
an amount of stream for the base that is manageable such as one gallon, a syringe is required to inject
a small enough amount of the concentrate to make 50 PPM. This droplet of oil will tend to separate
(float) to the surface.
A typical approach to making a concentration is as follows:
1. Acquire 10 liters of 0 PPM process water in a glass jar (plastic containers will draw the
hydrocarbons out of the prepared sample).
2. Separately, thoroughly mix 1 ml of the sample oil (type of oil to be found in stream) with 1 ml of
acetone. The oil will readily mix with the acetone and the acetone will act as an agent to
distribute the oil throughout the water.
3. Thoroughly mix the oil/acetone sample with the 10 liters of 0 PPM process water. This will make
a 100 ppm sample.
e.g.: 1ml (oil sample) x 1,000,000 = 100ppm
*
10,000 ml (water)
*
Actual amount is 99.9ppm due to overall volume of 10 2ml of oil/acetone mix.
This is not a precise method. Standing time, the volatility of the oil, operator measurements and
equipment will all contribute to errors in the blend. This should be used quickly and only when actual
process conditions cannot be sent to laboratory for calibration.