Apparatus:
4.1 Container, shall be made of no absorptive material
and large enough to provide at least 3 in {75 mm} of concrete in all directions
around the sensor of the temperature measuring device; concrete cover must also
be at least three times the nominal maximum size of the coarse aggregate.
4.2 Temperature Measuring Device, shall be capable of
accurately measuring the temperature of the freshly mixed concrete to ± 1°F [±0.5°C] throughout a range of 30°to120°F [0° to 50°C]. The temperature measuring device
shall require immersion of 3 in {75 mm} or less during operation.
4.3 Partial immersion liquid-in-glass thermometers (and
possibly other types) shall have a permanent mark to which the device must be
immersed without applying a correction factor.
4.4 Reference Temperature Measuring Device, shall be
readable and accurate to ±0.5°F [0.2°C] at the verification points in 5.1. A certificate or report
that verifies the accuracy shall be available in the laboratory for review. The
certificate or report shall provide documentation that the reference standard
used in the verification is traceable to NIST.
5. Calibration of Temperature Measuring
Device
5.1 Each temperature measuring device used for
determining temperature of freshly mixed concrete shall be calibrated annually,
or whenever there is a question of accuracy. This calibration shall be
performed by comparing the readings of the temperature measuring device at two
temperatures at least 30°F [15°C] apart.
5.2 Calibration of the temperature measuring device may
be made in oil or other suitable baths having uniform density if provision is
made to:
5.2.1 Maintain the bath temperature
constant within 0.5°F [0.2°C] during the period of the test.
5.2.2 Have both the temperature and
reference temperature measuring device maintained in the both for a minimum of
5 min before reading temperatures.
5.2.3 Continuously circulate the bath
liquid to provide a uniform temperature.
5.2.4 Slightly tap thermometers containing
liquid to avoid adhesion of the liquid to the glass if the temperature exposure
is being reduced.
Apparatus:
4.1 Container, shall be made of no absorptive material
and large enough to provide at least 3 in {75 mm} of concrete in all directions
around the sensor of the temperature measuring device; concrete cover must also
be at least three times the nominal maximum size of the coarse aggregate.
4.2 Temperature Measuring Device, shall be capable of
accurately measuring the temperature of the freshly mixed concrete to ± 1°F [±0.5°C] throughout a range of 30°to120°F [0° to 50°C]. The temperature measuring device
shall require immersion of 3 in {75 mm} or less during operation.
4.3 Partial immersion liquid-in-glass thermometers (and
possibly other types) shall have a permanent mark to which the device must be
immersed without applying a correction factor.
4.4 Reference Temperature Measuring Device, shall be
readable and accurate to ±0.5°F [0.2°C] at the verification points in 5.1. A certificate or report
that verifies the accuracy shall be available in the laboratory for review. The
certificate or report shall provide documentation that the reference standard
used in the verification is traceable to NIST.
5. Calibration of Temperature Measuring
Device
5.1 Each temperature measuring device used for
determining temperature of freshly mixed concrete shall be calibrated annually,
or whenever there is a question of accuracy. This calibration shall be
performed by comparing the readings of the temperature measuring device at two
temperatures at least 30°F [15°C] apart.
5.2 Calibration of the temperature measuring device may
be made in oil or other suitable baths having uniform density if provision is
made to:
5.2.1 Maintain the bath temperature
constant within 0.5°F [0.2°C] during the period of the test.
5.2.2 Have both the temperature and
reference temperature measuring device maintained in the both for a minimum of
5 min before reading temperatures.
5.2.3 Continuously circulate the bath
liquid to provide a uniform temperature.
5.2.4 Slightly tap thermometers containing
liquid to avoid adhesion of the liquid to the glass if the temperature exposure
is being reduced.
