Split-Type or Integrated Roughness Tester: How to Choose

What actually differs

An integrated unit puts the probe, electronics and screen in one housing. Pick it up, place it on the surface, read the number. For flat plates and shaft diameters it is the fastest option available.

A split unit separates the probe from the main body. The probe is palm-sized and fits into cavities, bore walls and deep grooves; the main unit stays in your hand or on a bench, so the screen is always in view.

When split is the only option

Bores, deep grooves, narrow slots and mould cavities: the integrated body simply will not fit.

Large or fixtured workpieces: a cast iron frame, a machine bed, a part already clamped in a fixture. You bring the probe to the part, not the part to the instrument.

Restricted space: working at height, inside a vessel, beside a pipe run. The main unit can sit somewhere stable while only the probe goes in.

In these three cases a split unit is not the better choice. It is the only choice.

When integrated wins

If you measure flat faces and outer diameters, the part comes to the bench, and you check dozens of pieces a day, an integrated unit is quicker to use and has no cable to break.

The cable is the weak point of any split system. Field abuse, a wheel rolling over it, or hard bending in cold weather all cause intermittent faults, which are the hardest kind to diagnose.

Three details when specifying

Removable probe: models that accept different probes cover more radii and depths. Fixed probes are cheaper but limited.

Cable length: too short and you cannot reach, too long and it tangles and attenuates the signal. Measure to your furthest point and add one metre.

Main unit format: a handheld body suits walking measurements, a benchtop body suits a fixed station. Some models work either way.

Summary

A split unit is not an upgrade of an integrated one. It is a different tool for parts you cannot reach. Decide where the measurement point is first; otherwise you will buy the wrong one.