A12P

Supported Applications

The Omega A12P series consists of rugged, all-stainless steel compost thermometers designed for monitoring interior temperatures in compost piles and windrows. These instruments are utilized in waste disposal, recycling, and mushroom farming applications to measure temperature within semi-solid media.

Operating Conditions & Performance

The A12P series features a sensitive bimetal helix sensing element located in the bottom two inches of the stem. When inserted into a medium, the instrument indicates the temperature at that specific depth (e.g., insertion to 36" measures conditions between 34 and 36"). The dial is driven by this mechanism with an accuracy of ±1% of full scale.

Performance specifications include:

• Maximum Head Temperature: 93°C (200°F)
• Dial Size: 76 mm (3") diameter
• Response Time: Once inserted, wait at least 45 seconds before reading the temperature. For stems over 36", if inserted with a protective sheath through a pre-cored hole, waiting three minutes is recommended.
• Dial Scales: Available in Fahrenheit (°F), Celsius (°C), or Dual scales depending on the model suffix.

Configuration Options

The series offers a wide range of configurations to accommodate different insertion depths and media densities. Key configurable dimensions include stem length, stem diameter, and temperature scale ranges.

• Stem Lengths: Available in 12", 24", 36", 48", 60", and 72" options.
• Stem Diameters: Models are offered with either a 6.35 mm (¼") diameter stem or a 7.94 mm (5/16") diameter stem for increased rigidity in longer lengths.
• Housing and Materials: The head and bezel are constructed from polished type 302 stainless steel, while the stem is made of Type 304 stainless steel. The dial face is anodized aluminum with a crystal made of unbreakable plastic.
• Temperature Ranges: Specific ranges include -40 to 160°F, 0 to 250°F/-20 to 120°C (Dual), and various Celsius scales such as 0 to 100°C. Graduations vary by range from ½° to 2°.
• Protective Sheath: A PVC sheath is provided for storage; the manual recommends keeping the stem in this sheath when not in use to prevent bending of the pointed tip.

Model Number Structure

The series uses a model numbering convention that identifies stem diameter and length. Models ending with "P" denote the 6.35 mm (¼") stem, while models ending with "PF" indicate the 7.94 mm (5/16") stem.

• Standard Stem: A12P through A48P cover lengths from 12 to 48 inches.
• Heavy-Duty Stem: The "PF" series includes models such as A12PF, A60PF, and A72PF. Note that the 5/16" diameter stem is available for all lengths from 12 to 72 inches.

Safety and Handling Notes

The pointed stem of the thermometer is very sharp; handling requires care to avoid bending, which renders the instrument inoperable. For insertion into semi-solids like compost, grasp the shaft about 6" back from the point and push on the stem only (not the head). Once inserted 6", move grip further back and repeat until fully seated.

Key Product Differences

The primary distinction within the A12P series is the stem diameter, which correlates with model suffixes. The "P" models feature a ¼" (6.35 mm) stainless steel stem suitable for shorter lengths up to 48 inches in standard configurations. The "PF" models utilize a thicker 5/16" (7.94 mm) stem and are available across the full length spectrum, including the extended 60-inch and 72-inch variants.

Temperature scale variations define the specific suffix following the model number (e.g., -0-250F/-20-120C). The series does not include electrical outputs or digital displays; all models are analog dial thermometers with an exterior reset adjustment and hermetically sealed construction to prevent fogging.