Pulp & Paper Stock Consistency Transmitters True Cost of Ownership

One of the objections I hear regarding passive mechanical consistency transmitters is the high cost of ownership that these systems purportedly have.

The thinking goes something like this.  Mechanical transmitters typically have a sensor in the line that protrudes into the flow in the line.  Sooner or later, that sensor will get hit and damaged and will need to be replaced.  Thus, to keep a a mechanical sensor operational requires that the sensor be replaced and represents an ongoing expense.  The alternative, a rotary transmitter is typically installed such that its sensor is wholly contained within a stilling chamber and is thus not likely to be hit and damaged.  Its cost of operation must be lower, right?

While there is some truth to this, it’s not the whole story – not by a long shot.
It’s true that passive mechanical systems do get hit from time to time and their sensors will need to be replaced.  It’s also true that rotary systems don’t often get damaged because their sensors are offset from the flow.   That said, what is not true is the notion that the cost of ownership for a rotary is far less than that for a mechanical. It isn’t.

Let me illustrate this with an example using my company’s C3000 sensor:
The TECO C3000 Consistency Sensor
A rotary system will cost you somewhere in the neighborhood of $30,000. Let’s assume that it will last five years before it will need to be replaced.  A complete TECO C3000 mechanical system, on the other hand,  will typically cost you somewhere under $7k. Let’s say you have to replace the C3000 sensor once per year.  Your annual cost, including the trade-in credit for the original sensor core, is under $2k per sensor.

Over five years you’ll pay less than half of what you’d paid for the rotary initially.  Let me say that again – you’d pay less than half of what you’d pay for the rotary.

Don’t get me wrong, rotary consistency transmitters are cool devices and they certainly have their positive points, but they ain’t cheap.  Passive mechanicals are way, way less expensive and you can use them to measure mostly the same consistency range that you would use a rotary to measure.  Properly applied, the TECO C3000 sensor will give you way more bang for the buck than any other system available in the world today.