Marposs81696AH8EAGauging Amplifier / Controller Electronics Unit, 100-240 V AC 50/60 Hz, for In-Process Dimensional Measurement

Product Description

What this part is

A Marposs gauging amplifier / controller electronics unit. Marposs builds in-process and post-process dimensional measurement systems for machine tools — the gauges that sit on a grinder, a hone or a lathe and measure the workpiece while it is being cut. This unit is the electronics half of such a system: it excites and conditions the signals from Marposs inductive gauging heads, LVDT-type transducers and measuring fixtures, converts them into dimensional readings, and passes the result to the machine control as size, tolerance-band or in-tolerance/out-of-tolerance signalling.

It is a measurement amplifier and controller, not a probe, not a display head on its own and not a general-purpose signal conditioner. It has no meaning without the gauge it belongs to.

Nameplate data

Marposs part number: 81696AH8EASupply: 100–240 V AC, 50/60 Hz — wide-range input, so no voltage selector to set wrongFunction: gauging amplifier / controller unit within a Marposs measurement systemOrigin: Italy (Marposs S.p.A., Bentivoglio, Italy)

Why the part number matters more than usual here:
Marposs supplies most of its gauging electronics as part of an engineered application, and the eight-digit part numbers identify a specific build for a specific gauge — the transducer type, the channel count, the calibration and the machine interface are all fixed by that number. The practical consequence is blunt: match the part number exactly against the unit you are replacing, and against the gauge documentation for your machine. Two Marposs amplifiers can be outwardly similar and electrically incompatible with each other’s heads. If your machine’s gauge documentation or the label on the failed unit reads 81696AH8EA, this is the part; if it reads anything else, it very probably is not.

The wide 100–240 V input is genuinely useful on a spare, because it removes one variable — the same unit suits a 120 V or a 230 V panel without strapping.

Why in-process gauging is worth keeping alive

On a production grinder, the gauge is what makes the process capable. It closes the loop on size, compensates for wheel wear, triggers the spark-out and the retract, and keeps a whole shift’s parts inside a few microns without an operator measuring anything. When the gauging electronics fail, the machine can usually still turn — it just cannot hold size, which means scrap, 100% manual inspection, or a stopped line. That is why gauge electronics spares get held on the shelf in the first place, and why a same-part-number unit is worth more than its face value when the machine is down.

Quantity and configuration

One electronics unit, new, as photographed.

What is not included

Gauging heads, probes or transducers, measuring fixture or bench, probe cables and extension leads, mains cord, machine interface cable and connectors, mounting brackets or panel hardware, display or operator terminal if separate, calibration masters or setting rings, calibration certificate, software or configuration data, and documentation. No calibration to your part or gauge is supplied or implied — the system must be mastered and set on installation.

Installation and setup notes

Confirm the incoming supply is within 100–240 V AC and that the mains earth is solid; gauging electronics resolve micron-level signals and are unforgiving of a poor earth or of screens landed at both ends. Route probe cables away from spindle drives, contactors and coolant pumps, and do not extend or splice them casually — gauge cables are part of the calibrated signal path. After installation the gauge must be mastered against setting rings or masters and the tolerance bands re-entered; a replacement amplifier does not inherit the previous unit’s calibration.

Interchange guidance

Direct interchange with other Marposs 81696AH8EA units. Other Marposs amplifier part numbers are application-specific builds, not equivalents — do not substitute on the basis of outward similarity or of a shared prefix. Where the exact number cannot be sourced, the correct route is Marposs or a Marposs service partner, who can identify the gauge from the machine and specify the current-generation electronics; that is a system change, not a module swap, and it normally means new heads and re-mastering as well.