Articulated arm

1. An articulated arm CMM comprising:

an articulated arm comprising a plurality of transfer members, a plurality of articulation members connecting at least two transfer members to each other, a coordinate acquisition member at a distal end, and a base at a proximal end;

at least two encoders mounted within the articulation members each encoder configured to measure rotation and comprising at least one read head at least one pattern, the at least two encoders comprising a first encoder and a second encoder; and

at least one monoblock housing configured such that the at least two encoders are positioned within a single monoblock housing, the single monoblock housing defining at least two axes of rotation between at least two transfer members, the first encoder positioned along a first of at least two axes to measure rotation about a first axis of rotation and the second encoder positioned along a second of the at least two axes to measure rotation about a second axis of rotation.

2. The articulated arm CMM of claim 1 wherein the monoblock housing comprises a removable cover portion.

3. The articulated arm CMM of claim 2 wherein the removable cover portion occludes an opening the housing through which an encoder can be inserted into the housing.

4. The articulated arm CMM of claim 1 wherein the housing comprises a hinge-receiving portion and a swivel receiving portion.

5. The articulated arm CMM of claim 1 wherein the at least two encoders are configured to detect rotation about at least two axes that are perpendicular to each other.

6. The articulated arm CMM of claim 1 wherein the at least two encoders can be inserted and removed independently.

7. An articulated arm CMM comprising:

an articulated arm comprising a plurality of articulated arm members, a coordinate acquisition member at a distal end, and a base at a proximal end; and

a gas spring counterbalance supporting the arm about a rotational point between a first articulated arm member closer to the base and an adjacent second articulated arm member further from the base than the first articulated arm member, the gas spring counterbalance providing support at a point along the second articulated arm;

wherein the gas spring counterbalance connects to the first articulated arm member at a point nearer to the rotational point than to the base.

8. The articulated arm CMM of claim 7 , wherein the gas spring counterbalance comprises an integral locking mechanism.

9. The articulated arm CMM of claim 7 , wherein the gas spring counterbalance comprises nitrogen gas.

10. The articulated arm CMM of claim 7 , wherein the gas spring counterbalance comprises a lock that can increase a resistance against movement of the gas spring counterbalance.

11. The articulated arm CMM of claim 10 , wherein the lock comprises a lever and a pushing pin that can open and close an aperture within the gas spring counterbalance, controlling gas flow.

12. An articulated arm CMM comprising:

an articulated arm comprising a plurality of articulated arm members, a coordinate acquisition member at a distal end, and a base at a proximal end; and

a gas spring counterbalance supporting the arm at a rotational point between two adjacent articulated arm members;

wherein rotation at the rotational point brings one of the two adjacent articulated arm members to a substantially horizontal position when the gas spring counterbalance is also brought to a substantially horizontal position.

13. The articulated arm CMM of claim 12 , wherein the gas spring counterbalance comprises an integral locking mechanism.

14. The articulated arm CMM of claim 12 , wherein the gas spring counterbalance comprises nitrogen gas.

15. The articulated arm CMM of claim 12 , wherein the gas spring counterbalance comprises a lock that can increase a resistance against movement of the gas spring counterbalance.

16. The articulated arm CMM of claim 15 , wherein the lock comprises a lever and a pushing pin that can open and close an aperture within the gas spring counterbalance, controlling gas flow.

17. An articulated arm CMM comprising:

an articulated arm comprising a plurality of articulated arm members, a coordinate acquisition member at a distal end, and a base at a proximal end; and

a pistol grip handle comprising electronics and removably connected to the articulated arm substantially at the coordinate acquisition member.

18. The articulated CMM of claim 17 , wherein the handle provides modular functionality.

19. The articulated CMM of claim 17 , wherein the electronics are thermally isolated from the articulated arm.

20. The articulated CMM of claim 17 , the handle is thermally isolated from the articulated arm.