C-Tech H1820, Product Manual, Page: 3 / 10

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I. Description
This instrument is suitable for measuring the theoretical maximum relative density of asphalt mixture
by vacuum method. It is used for asphalt mixture ratio design, road investigation or road construction
quality management to calculate void ratio and compaction degree. Not suitable for asphalt mixtures
with porous aggregates with water absorption greater than 3%.
II. Technical specifications
Power supply 220v±10℅ 50Hz
Vibration motor input power 40w
Handheld digital vacuum gauge, negative pressure range 0 - 100kpa
Test requirement 3.7Kpa(±0.3)
Working mode manual
Container volume 18000ml Class A negative pressure container
Vibration mode Continuous vibration
Dimensions 440×440×520 mm
Weight About 30kg
III. Operation
① . Connect the equipment to the vacuum pump and vacuum gauge.
② . Turn on the vacuum gauge. For operation methods, refer to
V.
Digital Vacuum Gauge. The
vacuum gauge displays the current atmospheric pressure and temperature.
③ . Start the vacuum pump and the value of the vacuum gauge decreases. When the observed value
is 3.7kpa (± 0.3), turn off the vacuum pump to maintain the pressure. Start the vibration motor,
observe the bubbles in the container until there are no bubbles, then turn off the vibration
motor(the knob on the left side of the switch is used to set the vibration time). Observe the
vacuum gauge. When the pressure exceeds the range of 3.7Kpa(±0.3), turn on or off the vacuum
pump in time to maintain the pressure.
④ . After the test, open the top switch of the container. Slowly release the pressure to gradually