Petroleum testing is the analysis during upstream, midstream, and downstream production processes of petroleum products. It is most commonly used to test petroleum product, its product components, byproducts of crude oil, fuel, natural gas, upstream oil and gas and other formats of petroleum. - Automatic calibration procedure, graphic display. Multi-point temperature calibration, can be added by user. It has tube locking function, can avoid influencing accuracy when tube is moved for high viscosity.