When a plant loses position, the fastest fix is not always the best fix. I know that because my job is to coordinate replacement parts while production is waiting. In the past nine years, I’ve handled more than 200 rush orders for encoders, sensors, and measurement equipment—including more than a few same-day deliveries of SICK absolute encoders. I’ve seen the replace-first approach save a shift. I’ve also seen it make a bad day worse.
What We’re Comparing
This article compares two ways to respond to a machine that suddenly loses position or measurement accuracy:
Route A: Replace first. Order or install a SICK absolute encoder, swap the part, and get back to running. This route assumes the encoder is the cause.
Route B: Diagnose first. Use test tools—a data logger, an electrician's multimeter, or a simple load-cell test—to confirm what is actually failing before spending money on parts.
I compare them on three dimensions: time to line running, certainty about the root cause, and final cost after every fee is added.
Dimension 1: Time to Line Running
Route A looks faster. If you have a spare on the shelf and the machine is down, swapping the encoder can take under an hour. In a March 2024 case, a maintenance lead needed an absolute encoder for a rotary table. The normal lead time from the OEM was five days. We rushed a SICK absolute encoder to them in about 22 hours. They installed it in 45 minutes. The axis still lost position on the third cycle. The real problem was a crushed cable in the energy chain—not the encoder.
The data logger later showed the signal dropping whenever the cable moved. Route A had cost two days of downtime before anyone looked at the cable. Route B would have found that in the first 20 minutes.
I don’t want to imply Route A is wrong. When an encoder shaft is visibly broken, no amount of testing will fix it. But the fastest route to startup is the one that matches the fault. If you don’t know the fault, replacement is a guess. Guesses are slow.
Dimension 2: Diagnostic Certainty
A SICK absolute encoder has a genuine technical advantage: it reports absolute position after a power loss without a homing run. In an application that needs multi-turn position at startup, an absolute encoder is the right feedback family. What an absolute encoder cannot do is verify its own cable, connector, power supply, PLC input card, or grounding. Those are parts of the same measurement loop.
That’s why I use certainty as a comparison criterion. If you only compare encoder brand A versus brand B, you are comparing components. If you compare replace-first versus diagnose-first, you are comparing outcomes.
I don’t have hard data on industry-wide premature encoder replacements. What I can tell you anecdotally is that the problem is real. In the rush calls I handle, the first encoder replacement does not fix the machine often enough to skip basic checks. I would guess the number is somewhere between 15 and 25 percent—maybe higher in plants with older wiring.
The electricians multimeter is a spot-check tool. A data logger is the one that creates a shift record. If a machine only loses position after running for two hours, or at the same time every night, you will not catch that with a quick voltage check. Logging the signal over time gives you evidence instead of another guess.
Dimension 3: Total Cost and Hidden Fees
Route A has a visible price: the SICK absolute encoder, freight, and installation labor. The hidden costs show up when the connector is wrong, the protocol doesn’t match, the flange differs, or no configuration tool is available. An absolute encoder is not one universal part.
As of early 2025, I still see customers quoted a “replacement” encoder that looks close but is not correct for the application. A nameplate photo prevents more rush orders than any vendor promise. (Note to self: always ask for the nameplate before quoting.)
I’ve learned to ask “what is not included” before asking “what is the price.” The same logic applies to repair advice. If a vendor says “replace it and see,” ask what they measured. A vendor who lists all fees upfront, and shows you test results, usually costs less in the end.
Testing Tips That Prevent Repeat Rush Orders
If you are still unsure whether to follow Route A or Route B, run a short diagnostic sequence first.
1. Check the power supply at the connector
Use an electrician's multimeter with a DC voltage range. Measure at the encoder connector, not just at the power supply. A loose terminal can look fine at one end and fail under load. Also check the shield and grounding path if the machine history suggests electrical noise.
2. Use data loggers for intermittent faults
Data loggers are most useful when a fault is slow, recurring, or related to temperature, humidity, or time. For example, a 4–20 mA signal that drops every afternoon can be captured on a data logger and shown to the maintenance team. For high-speed encoder lines, a PLC diagnostic buffer or an oscilloscope may be needed. But in many plant faults, a data logger is still the quickest way to prove whether the problem follows a pattern.
3. If the fault is in weighing, test the load cell first
A common separate search is “how to test a Rice Lake load cell.” The procedure starts with the same idea: measure before replacing. A load cell is a strain-gauge bridge, not a digital encoder. You need a multimeter with a millivolt range. Follow the manufacturer’s manual for pinout, measure the excitation voltage at the cell, check the output with no load, and then apply a known weight. If the output does not rise as expected, trace the cable and connectors before replacing the cell. Rice Lake load cells are common, so this method applies to many plants.
What About the Search “SICK real thermometer high fever”?
If you searched for “SICK real thermometer high fever,” I need to stop you before you buy an industrial sensor for a medical problem. SICK is an industrial automation company. It does not make home fever thermometers. If someone has a high fever and you need a real thermometer, choose a medical-grade clinical device and follow qualified health advice.
If you are looking for industrial temperature monitoring instead, the right tool is usually a data logger with a calibrated temperature probe—not an encoder and not a consumer fever thermometer.
Which Route Should You Choose?
There is no universal winner. The choice depends on what you know before you act.
Choose Route A when:
- The encoder shaft, coupling, or connector is visibly damaged.
- The machine cannot run at all, and you have the exact spare part on hand.
- The fault message points specifically to the encoder, and you have already verified supply voltage and cable continuity.
- The application requires absolute position retention after power loss—this is where a SICK absolute encoder earns its place.
Choose Route B when:
- The fault comes and goes.
- The wiring has moved, been repaired, or been exposed to oil, water, or vibration.
- The same error returned after a recent encoder replacement.
- More than one axis or instrument is showing unusual readings.
- You are dealing with a load cell or weighing indicator rather than a motion feedback problem.
If the evidence says the absolute encoder is dead, I would rather see a SICK absolute encoder arrive than a look-alike with no application support. But if the evidence says “open cable” or “missing supply,” the most expensive thing you can do is replace the encoder anyway. In a rush, a real diagnosis is not wasted time. It is the fastest way to make the next order the last one.
