Sampling techniques Flashcards
1
Q
Explain how to handle a ruttner sampler, what is the advantages and drawbacks?
A
- Water sampler
- Thermometer and measuring tape
- Easy to measure at different depths
- If testing for metals, make sure equipment is not in metal
- Not good if the water is flowing
2
Q
Explain how to handle an Ekman sampler, what is the advantages and drawbacks?
A
- Grabs the sediment
- Good for sampling bottom dwellers
- Good for coarse or loose material
- No layers since the sample is disturbed and mixed
- Mix the sample afterwards
3
Q
Explain how to handle a corer, what is the advantages and drawbacks?
A
- You get a sediment core
- When taking it up, plug it under the water surface otherwise you will lose your sample.
- Can see sediment layers and see variations
- Not good for loose material
4
Q
Explain how to handle a peristaltic pump, what is the advantages and drawbacks?
A
- Uses negative pressure to pump up water, suction
- Can go down to 10 meters, but you get problems at 8 so 7 works
- Not suitable for volatile substances
- Can use this if you don’t want it to get exposed to oxygen
5
Q
Explain how to handle a bailer, what is the advantages and drawbacks?
A
- Plastic tube (with a valve)
- Cheap and easy to use, can take a new one for each sample
- Bad for circulation of groundwater
- Risk of losing volatile ompounds
- Oxidation, since it is not closed
6
Q
Explain how to handle a riffle splitter, what is the advantages and drawbacks?
A
- Devides the sample into two subsamples
- Based on normal distribution
- The sample must be dry
- The splitter must be placed on a horizontal and flat surface
- Pour the sample from a container that is as long as the splitter
7
Q
Explain how to handle a pH-meter, what is the advantages and drawbacks?
A
- Calibrate, to make sure there is no instrument drift. Use calibration liquids with pH 4, 7 and 10
- Take approx 3 measurments to take an average of the pH/conductivity
