The phrase "are two orders of" is correct and usable in written English.
It can be used when discussing categories, classifications, or types of something, indicating that there are two distinct groups or levels.
Example: "In the restaurant, there are two orders of pasta: the classic marinara and the creamy Alfredo."
Alternatives: "two categories of" or "two types of".
These regional markets are two orders of magnitude smaller than the American market, ranging from approximately 100 to 300 positions.
These transfer payments are two orders of magnitude larger than the corresponding rise in Trade Adjustment Assistance benefits.
Graphene sheets are two orders of magnitude less massive than similar devices made of silicon and so can measure signals at much higher frequency.
Here we use gas-dynamic forces to generate free-flowing, sub-micron, liquid sheets which are two orders of magnitude thinner than anything previously reported.
LODs calculated according to traditional protocols (three times the standard deviation of the noise) yield values that are two orders of magnitude lower.
Mobility lifetime products of films from our novel filaments are two orders of magnitude higher than those of samples from Ta wires.
This work also presents the first measurements of gas liquid mass transfer coefficients in milliliter-scale reactors, which are two orders-of-magnitude smaller than systems for which mass transfer coefficients have been reported earlier.
For pure superconducting materials, we estimate that SQUID measurements are three orders of magnitude below the MFMMS sensitivity (10−9 cc).
The interfacial rheological parameters are three orders of magnitude lower than those in the bulk.
Honeybees have fascinating social structure and advanced societies despite having brains that are five orders of magnitude smaller than humans.
There are three orders of magnitude difference between liquids and solid particles for thermal conductivity.
