Soil Pocket Penetrometer also known as hand penetrometer is made of stainless steel and used to determine soil characteristics. It is a simple, lightweight, handheld device to make instant estimates of unconfined compressive strength of cohesive soil. Although it doesn’t replace laboratory Unconfined Compressive Strength Test Systems for determination of unconfined shear strengths, the Pocket Penetrometer is useful for quick estimates.
OSHA specifies it for soil strength test estimates when evaluating the stability and safety of trench excavations and mix design sample. Such soil trench stability evaluations can determine if you need to increase slope angles or to shore excavations. You can purchase it in the Soil Classification Set which includes various tools and instruments for field evaluation and classification.
0.25in (6.4mm) diameter penetration piston is pushed into the soil surface to a groove machined on the piston at 0.25in (6.4mm) depth. Penetration test resistance from the calibrated steel spring is registered on an integrated scale engraved on the penetrometer barrel with a cast aluminum base. Scale units are in tons per square foot (tsf) or kg/cm² and a sliding indicator ring retains the maximum reading until reset.
The pocket penetrometer for cohesive soils features a heavy-duty stainless steel construction that guarantees a long, corrosion-free lifespan. Its calibrated spring, loading piston, and penetrometer body are plated to resist rust, ensuring dependable performance in diverse environments. Additionally, an optional adapter foot can be attached to increase the piston diameter from 0.25 inches (6.4mm) to 1 inch (25mm), expanding the surface area by 16 times for testing.
Features:
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Instant unconfined compressive strength test of cohesive soil sample
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Scale units engraved directly in tsf or kg/cm²
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Indicator ring retains maximum reading
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Stainless steel
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Meets OSHA for soil trench stability evaluations
Included Items:
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Soil Pocket Penetrometer for Cohesive Soils
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Pouch
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Weight 1 LB
Range 0–4.5tsf
Product Dimensions 0.75 x 6.6in (19 x 168mm), Dia.x L
Accessories:
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Adapter Foot Attachment increases the probe diameter to 1in (25mm) for 16 times the piston area
Soil Pocket Penetrometer Overview
Soil Pocket Penetrometer is a must have tool used in geotechnical engineering to test the compaction and bearing capacity of soil sample in situ. This tool for cohesive soils is valuable because it gives immediate feedback on soil quality which is very important for construction, agricultural and environmental applications. This overview will cover the design, functionality and application of the soil pocket penetrometer in soil testing.
What is a Pocket Penetrometer?
A pocket penetrometer for cohesive soils is a handheld device to test the compaction and bearing capacity of soil. It is a simple, lightweight tool that gives immediate feedback on soil quality, it’s an essential tool for geotechnical engineers, construction and agricultural professionals. The device is designed to assess the unconfined compressive strength of fine-grained cohesive soil, providing rapid estimates of soil strength.
The pocket penetrometer for cohesive soils is a stainless steel unit with a diameter loading piston that is pushed into the soil to 0.25in (6.4mm) depth. The penetration resistance from the loading spring is registered on a permanent scale units on the piston barrel which reads approximate unconfined compressive strength in tons per square foot (tsf) or kg/cm². An indicator sleeve retains the reading when the piston is released for easy and accurate measurement.
The pocket penetrometer is a must have tool for soil trench stability evaluation as it helps to determine if slope angle need to be modified or if shoring is required to support excavations. It is also used for visual classification of cohesive soils to give quick and reliable method of determining soil density in tons/sq.
Soil Penetrometer Design and Construction
Components and Materials:
A soil pocket penetrometer consists of cast aluminum base and stainless steel penetration needles for durability and corrosion resistance. It’s compact and portable with longer gear rack for deeper penetration. The penetrometer with longer gear rack, wooden block and has 6 needles that can be used to measure penetration resistance at different points.
Penetration Needles:
The 6 stainless steel needles are used to determine soil compaction test with a penetrometer with longer gear rack. These needles are designed to penetrate the soil with minimal friction to give a reliable measurement of penetration resistance. The number and sharpness of the needles are critical to the accuracy of the measurement.
Functionality and Operation
Using the Penetrometer:
The operation of a pocket penetrometer is easy. The device is manually pushed into the soil and the penetration resistance is measured by the depth the needle can penetrate under a standard force test. This is indicated on the device's graduated scale, displaying the penetration resistance in pounds.
Calibration:
Accuracy of penetration resistance is important for soil testing with mix design. The penetrometer is calibrated to ensure the reading is consistent and repeatable. Calibration is done by setting the device against known penetration resistance such as a wooden block and recording the values and adjust as necessary to ensure accuracy.
Applications in Soil Testing and Unconfined Compressive Strength
Quality Assessment:
Soil quality is a significant issue in construction and agriculture. The pocket penetrometer allows for quick testing and assessment of soil compaction across construction sites, farms, and other land areas. Compacted soil can impact the stability of structures and hinder plant growth by restricting root penetration.
Consistency and Compaction:
The device is used to test the consistency of soil mixtures and compaction of subgrades and backfills in construction. It helps to determine if the soil has been compacted to the specifications required to support structures such as buildings and roads.
Agricultural Applications:
In agriculture, a penetrometer assists farmers in identifying the ideal times for planting and harvesting by offering insights into soil compaction levels. Since compaction can hinder root growth and reduce crop yields, timing and precision are essential for optimal results.
Benefits of Pocket Penetrometer with Corrosion Free Service Life
Efficiency and Ease of Use:
One of the advantages of pocket penetrometer is its efficiency. It gives immediate feedback so you can adjust on the spot the soil handling or compaction process. The device is easy to use and doesn’t require extensive training, so it’s usable by engineers, construction workers and farmers.
Portability and Durability:
Thanks to its compact size and sturdy design, the penetrometer is highly portable and suitable for various field conditions. Its stainless steel and cast aluminum base materials guarantee that the device remains functional and reliable even in challenging environments.
Soft Soils Challenges
While pocket penetrometers have many advantages, they also have limitations. The measurement accuracy can be affected by the soil moisture content and presence of stones or other foreign bodies. The device may not provide enough penetration depth for some applications and may require other methods or tools for deeper soil analysis.
Tips to Use
To get accurate and reliable reading with pocket penetrometer:
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Calibration: Before using the pocket penetrometer, calibrate it to measure unconfined compressive strength of cohesive soils. Calibration is done by setting the device against known penetration resistance such as a wooden block and record values and adjust as necessary to ensure accuracy.
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Soil Preparation: Clean the soil surface from debris or loose materials. Make sure the soil is moist but not waterlogged as this can affect the measurement.
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Penetration: Hold the pocket penetrometer vertically and push the diameter loading piston into the soil to a depth of 0.25in (6.4mm). Apply gentle and consistent pressure to avoid compacting the soil further.
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Reading: Take note of the reading on the permanent scale on the piston barrel which indicates the approximate unconfined compressive strength of the soil in tons per square foot (tsf) or kg/cm².
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Adapter Foot Attachment: For testing very soft soils or soft materials, use the optional adapter foot attachment which increases the piston area 16 times. This attachment is useful for testing soft materials that may not give accurate reading with the standard piston.
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Maintenance: Regularly inspect the pocket penetrometer for any signs of wear or damage. Clean the device after each use and store it in dry place to ensure corrosion free service life.
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Training: Get to know how to operate and maintain the pocket penetrometer. While the device is user-friendly, proper training is essential for ensuring accurate results.
By following these tips to use, you will get accurate and reliable reading with your pocket penetrometer, making it a must have tool for soil trench stability evaluation, visual classification of cohesive soils and other geotechnical applications.
Conclusion
The pocket penetrometer is a must have tool for professionals in geotechnical engineering, construction and agriculture mixture proportions. Its design with stainless steel penetration needles and durable frame allows quick and reliable assessment of soil compaction and quality. This tool delivers essential data on penetration resistance, ensuring that soil conditions meet the necessary standards for various land uses, promoting safer construction and more productive agricultural results. The soil pocket penetrometer's simplicity and efficiency make it an essential addition to the toolkit of anyone working in the field.