'keep them consistent' is correct and usable in written English.
You could use it in a variety of contexts, such as in a work instruction manual, to remind people to maintain certain standards. For example, "It is important to keep measurements accurate and consistent throughout the manufacturing process."
A lot of ingenuity evidently goes into the elaboration of modern flat-Earth theories to keep them consistent.
It's almost as if people have some sort of control over their actions and keep them consistent with social norms.
Moreover, a conservative interpolation operator is devised for conservatively remapping values in order to keep them consistent across different overlapping grids.
Therefore, it is necessary to make the relationships of different tool data repositories visible and keep them consistent with each other.
Therefore, the database manager will need to keep them consistent with any changes in the structure files required by modifications in the online interface.
Headlines can be larger, but keep them consistent.
He got the product mix right, made sure the stores were stocked well, kept them consistent up and down the country and was clear about strategy.
It's expensive to take the measurements, because you have to train people and keep them disciplined and consistent, and working efficiently to take the measurements.
First, Siwko and colleagues used fewer animals as donors and did not keep them at a consistent age when tissue was harvested.
Use good horsemanship instead: If your horse starts to slow down, squeeze or nudge slightly with your heels and lower calves while you are coming down from the post to keep them in a consistent trot.
Mr. Kibbe and Mr. Armey both went of out of their way to say that their efforts to rally new members around their legislative goals and to keep them Tea Party-correct are consistent with those of Representative John A. Boehner of Ohio, the presumed new speaker of the House.
