Summary
  This instrument is designed and made as per T 0711-2011 and ASTM D2041 Standard Test Method for Theoretical Maximum Specific Gravity of Bituminous Mixtures(Vacuum process) in JTG E20-2011.It is suitable to determine the theoretical maximum specific gravity of bituminous mixtures by vacuum process. It is used to design the ratio of bituminous mixtures, survey the road condition or calculate the void ratio and compactness of road construction.It is not available to determine the lacunose bituminous mixtures which water absorption overs 3%.

I. Main technical features
1. It adopts single chip machine technology to vacuumize, shake, fill air and relieve pressure automatically.
2. Equipped with a high-accuracy absolute pressure sensor, the negative pressure can reach 3.7 kPa±0.3 kPa.
3. The working status of the vacuum pump can be reflected by a vacuum meter.
4. It equips a water buffer device to prevent the water in the negative pressure container from flowing into the vacuum
    pump.
5. It can determine two samples at the same time.Test efficiency is high.The structure is reasonably designed. It is easy to
    use.

II. Main technical specifications
1. Power supply：      AC(220±10%)V, 50Hz.
2. Volume of vessel：    4000ml×2
3. Power of vacuum pump：  160W
4. Negative pressure：   3.7 kPa（27.75mmHg）.   Allowable bias is ±0.3 kPa.
5. Power of shaking machine： 30W
6. Dimension：   510mm×520mm×380mm              

III. Optional accessory
1. Constant temperature water bath：   HWY-1 Low-temperature water bath