Experiment 8 SAMPLING TECHNIQUES
OBJECTIVES:
• To develop different types of sampling techniques.
• Use as one of major processes in technical analyzing.
• Develop accuracy when measuring samples.
INTRODUCTION:
Analytical procedure consist several important steps. The specific analytical procedure chosen depends on how much sample is available and, in a broad sense, how much analyte is present. Then, discuss a general classification of the types of determinations based on these factors. After selecting the particular method to be used, a representative sample should be in hand first. The sampling process involves obtaining a small amount of material that accurately represents the bulk of the material being analyzed. Acquiring a representative sample is a statistical process. Sampling is the most difficult step in the entire analytical process and step that limits the accuracy of the procedure. Then, sampling for a chemical analysis necessarily involves statistics because conclusions will be drawn about a much larger amount of material from the analysis of a small laboratory sample.
EXPERIMENTAL SECTION
Apparatus used to gather data are, six (6) pieces of 150 ml beakers for sample container; four (4) pieces of 250 ml beakers for another set of sample; a spatula for separating samples; and an improvised scoop for scooping samples.
The samples needed in the experiment were 100 grams of the following: “monggo” beans, rice, peanuts, corn kernels, black pepper, and “Watermelon” seeds.
PROCEDURES
Layer the different samples in a beaker then scoop the layered sample approximately five (5) to ten (10) grams and then weigh it. Repeat the early procedure and record the weighed sample. Create a paper cone to split the sample from the top so that, it can separate the mixed samples. Then, divide the separated samples by quartering and making a triad selection. Then from the triad, select one part and subject to fractional shoveling and again divide into three (3), then in each part , gather ten (10) scoops per pile.
SET-UP(sorry set up images cannot be retrieve)
SCOOPING
BARE HAND
PAPER CONE RIFLE SPLITTING
CONING AND QUARTERING
Top view of beakers
FRACTIONAL SHOVELING
*10 scoops per pile
* combination of samples
DATA AND RESULTS(tsaka yung table)
Table 1. SCOOPING
SAMPLES WEIGHT OF THE SAMPLES (grams)
Peanuts 0.7554 g
“Watermelon” seeds 0.6970 g
Black pepper 0.4374 g
Corn kernels 1.5728 g
“Monggo” beans 0.7737 g
Rice grains 0.8077 g
TOTAL 5.044 g
Table 2. BARE HAND GRAM SAMPLING
SAMPLES WEIGHT OF THE SAMPLES (grams)
Peanuts 0.4003 g
“Watermelon” seeds 2.0651 g
Black pepper 0.7872 g
Corn kernels 1.6469 g
“Monggo” beans 0.7520 g
Rice grains 0.2641 g
TOTAL 5.9156 g
Table 3. PAPER CONE RIFFLE SPLITTING
SAMPLES WEIGHT OF THE SAMPLES (grams)
Peanuts 0.9841 g
“Watermelon” seeds 1.4261 g
Black pepper 1.6859 g
Corn kernels 1.2572 g
“Monggo” beans 0.5641 g
Rice grains 2.1888 g
TOTAL 9.1062 g
Table 4. CONING AND QUARTERING
SAMPLES WEIGHT OF THE SAMPLES (grams)
Peanuts 2.1647 g
“Watermelon” seeds 0.9013 g
Black pepper 0.9938 g
Corn kernels 0.9175 g
“Monggo” beans 1.2465 g
Rice grains 2.4830 g
TOTAL 8.7068 g
Table 5. FRACTIONAL SHOVELING
SAMPLES WEIGHT OF THE SAMPLES (grams)
Peanuts 1.379 g
“Watermelon” seeds 1.528 g
Black pepper 1.985 g
Corn kernels 0.977 g
“Monggo” beans 2.050 g
Rice grains 2.152 g
TOTAL 10.071 g
Table 6. FINAL TABULATION
SAMPLES WEIGHT BEFORE WEGHT AFTER
Peanuts 12.100 g 12.115 g
“Watermelon” seeds 12.010 g 12.123 g
Black pepper 12.06 g 12.13 g
Corn kernels 12.081 g 12.12 g
“Monggo” beans 12.14 g 12.26 g
Rice grains 12.056 g 12.11 g
TOTAL 72.447 g 72.858 g
DISCUSSION
The five (5) tables above show, the results where five different sampling techniques are done. Whereas the sixth table contains the final tabulation of the five supplementary results in the previous sampling techniques.
In random sampling, each item or element of the population has an equal chance of being chosen at each draw. A sample is random if the method for obtaining the sample meets the criterion of randomness (each element having an equal chance at each draw). The actual composition of the sample itself does not determine whether or not it was a random sample.
CONCLUSION
Conceptually, simple random sampling is the simplest of the probability sampling techniques. It requires a complete sampling frame, which may not be available or feasible to construct for large populations. Even if a complete frame is available, more efficient approaches may be possible if other useful information is available about the units in the population.
Advantages are that it is free of classification error, and it requires minimum advance knowledge of the population. It best suits situations where not much information is available about the population and data collection can be efficiently conducted on randomly distributed items. If these conditions are not true, stratified sampling or cluster sampling may be a better choice.
REFERENCES
- Wikes University Center for Environmental Quality Environmental Engineering and Earth Sciences Total Dissolved Solids.
- Wikipedia the free encyclopedia
- L.T. Enerva., “Laboratory Manual in Technical Analysis”, Department of natural Sciences, Polytechnic University of the Philippines sta. mesa Manila, Philippines.
• To develop different types of sampling techniques.
• Use as one of major processes in technical analyzing.
• Develop accuracy when measuring samples.
INTRODUCTION:
Analytical procedure consist several important steps. The specific analytical procedure chosen depends on how much sample is available and, in a broad sense, how much analyte is present. Then, discuss a general classification of the types of determinations based on these factors. After selecting the particular method to be used, a representative sample should be in hand first. The sampling process involves obtaining a small amount of material that accurately represents the bulk of the material being analyzed. Acquiring a representative sample is a statistical process. Sampling is the most difficult step in the entire analytical process and step that limits the accuracy of the procedure. Then, sampling for a chemical analysis necessarily involves statistics because conclusions will be drawn about a much larger amount of material from the analysis of a small laboratory sample.
EXPERIMENTAL SECTION
Apparatus used to gather data are, six (6) pieces of 150 ml beakers for sample container; four (4) pieces of 250 ml beakers for another set of sample; a spatula for separating samples; and an improvised scoop for scooping samples.
The samples needed in the experiment were 100 grams of the following: “monggo” beans, rice, peanuts, corn kernels, black pepper, and “Watermelon” seeds.
PROCEDURES
Layer the different samples in a beaker then scoop the layered sample approximately five (5) to ten (10) grams and then weigh it. Repeat the early procedure and record the weighed sample. Create a paper cone to split the sample from the top so that, it can separate the mixed samples. Then, divide the separated samples by quartering and making a triad selection. Then from the triad, select one part and subject to fractional shoveling and again divide into three (3), then in each part , gather ten (10) scoops per pile.
SET-UP(sorry set up images cannot be retrieve)
SCOOPING
BARE HAND
PAPER CONE RIFLE SPLITTING
CONING AND QUARTERING
Top view of beakers
FRACTIONAL SHOVELING
*10 scoops per pile
* combination of samples
DATA AND RESULTS(tsaka yung table)
Table 1. SCOOPING
SAMPLES WEIGHT OF THE SAMPLES (grams)
Peanuts 0.7554 g
“Watermelon” seeds 0.6970 g
Black pepper 0.4374 g
Corn kernels 1.5728 g
“Monggo” beans 0.7737 g
Rice grains 0.8077 g
TOTAL 5.044 g
Table 2. BARE HAND GRAM SAMPLING
SAMPLES WEIGHT OF THE SAMPLES (grams)
Peanuts 0.4003 g
“Watermelon” seeds 2.0651 g
Black pepper 0.7872 g
Corn kernels 1.6469 g
“Monggo” beans 0.7520 g
Rice grains 0.2641 g
TOTAL 5.9156 g
Table 3. PAPER CONE RIFFLE SPLITTING
SAMPLES WEIGHT OF THE SAMPLES (grams)
Peanuts 0.9841 g
“Watermelon” seeds 1.4261 g
Black pepper 1.6859 g
Corn kernels 1.2572 g
“Monggo” beans 0.5641 g
Rice grains 2.1888 g
TOTAL 9.1062 g
Table 4. CONING AND QUARTERING
SAMPLES WEIGHT OF THE SAMPLES (grams)
Peanuts 2.1647 g
“Watermelon” seeds 0.9013 g
Black pepper 0.9938 g
Corn kernels 0.9175 g
“Monggo” beans 1.2465 g
Rice grains 2.4830 g
TOTAL 8.7068 g
Table 5. FRACTIONAL SHOVELING
SAMPLES WEIGHT OF THE SAMPLES (grams)
Peanuts 1.379 g
“Watermelon” seeds 1.528 g
Black pepper 1.985 g
Corn kernels 0.977 g
“Monggo” beans 2.050 g
Rice grains 2.152 g
TOTAL 10.071 g
Table 6. FINAL TABULATION
SAMPLES WEIGHT BEFORE WEGHT AFTER
Peanuts 12.100 g 12.115 g
“Watermelon” seeds 12.010 g 12.123 g
Black pepper 12.06 g 12.13 g
Corn kernels 12.081 g 12.12 g
“Monggo” beans 12.14 g 12.26 g
Rice grains 12.056 g 12.11 g
TOTAL 72.447 g 72.858 g
DISCUSSION
The five (5) tables above show, the results where five different sampling techniques are done. Whereas the sixth table contains the final tabulation of the five supplementary results in the previous sampling techniques.
In random sampling, each item or element of the population has an equal chance of being chosen at each draw. A sample is random if the method for obtaining the sample meets the criterion of randomness (each element having an equal chance at each draw). The actual composition of the sample itself does not determine whether or not it was a random sample.
CONCLUSION
Conceptually, simple random sampling is the simplest of the probability sampling techniques. It requires a complete sampling frame, which may not be available or feasible to construct for large populations. Even if a complete frame is available, more efficient approaches may be possible if other useful information is available about the units in the population.
Advantages are that it is free of classification error, and it requires minimum advance knowledge of the population. It best suits situations where not much information is available about the population and data collection can be efficiently conducted on randomly distributed items. If these conditions are not true, stratified sampling or cluster sampling may be a better choice.
REFERENCES
- Wikes University Center for Environmental Quality Environmental Engineering and Earth Sciences Total Dissolved Solids.
- Wikipedia the free encyclopedia
- L.T. Enerva., “Laboratory Manual in Technical Analysis”, Department of natural Sciences, Polytechnic University of the Philippines sta. mesa Manila, Philippines.
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