How do I test my air meter?
How do I test my air meter?
Use the hand pump to pressurize the air chamber until the gauge hand reaches the initial pressure line. Allow the air to cool for a few seconds, then pump or bleed off air as needed and tap the gauge lightly to stabilize the indicating hand.
What is Super Air meter concrete test?
Super Air Meter (SAM) is a modified version of a conventional Type B Concrete Air Meter. The SAM determines both the total air content and air void spacing factor of fresh concrete specimens in under 10 minutes.
What is a Type A air meter?
The James Instruments™ ASTM “Type A” Air Meter is used to determine the amount of entrained air in freshly mixed concrete. The A-AA-1100 “Type A” Pressure Air Meter needs little or no maintenance and is the meter of choice in certain regions.
What is a good air content in concrete?
Concrete having a total air void content of about 6.5% seems optimal. A mix having 6.5% total air voids will have approximately 1.5% entrapped air voids and 5.0% entrained air voids. Entrapped air is the larger bubbles formed in the mixing process and does not provide much protection against freeze-thaw action.
How do you measure air content in concrete?
Air Content – Air content is calculated by subtracting the unit weight, ρ, from the theoretical unit weight, T, divided by the theoretical unit weight, T, multiplied by 100 as shown below.
What is calibration of air explain in detail?
Calibration: an instrument’s measuring accuracy relative to a known concentration of test gas. Calibration gas gives air monitors a reference point for monitor readings in the actual work environment. Calibrate an instrument in the same environmental conditions it will monitor in order to ensure accurate readings.
How do you clean a concrete air meter?
open, add water with a syringe through the petcock that has the pipe extension below until all air is forced out opposite petcock. Leave both petcocks open. to a little beyond the predetermined initial pres- sure line. Wait a few sec- onds for compressed air to cool to normal temperature.
What is the SAM number in concrete?
The SAM number is a value calculated from the pressure curves produced in the test. A spacing factor of 0.008†is shown. This value is recommended by ACI 201 as the value needed to produce frost durable concrete. There is almost a linear trend between these two measurements.
What does an air meter measure?
An air flow meter is a device that measures air flow, i.e. how much air is flowing through a tube. It does not measure the volume of the air passing through the tube, it measures the mass of air flowing through the device per unit time.