Within the Dakota NDT range, thickness and corrosion gauges are spread across several levels of capability. The Dakota ZX-3 is an entry-level model with a numerical display, while the Dakota CMX1-DL is an advanced corrosion gauge with an A-Scan display and data storage. This guide helps to work out when the basic gauge is enough and when it becomes necessary to move up to an instrument with higher-level functions.
What the Dakota ZX-3 is
The Dakota ZX-3 is an ultrasonic thickness gauge with a digits-only display (not graphical), designed for quick measurements and immediate reading of the numerical value. According to the official Dakota specifications:
- Pulse-Echo measuring range: 0.63 – 914.4 mm (wide range)
- Resolution: 0.01 mm
- Velocity calibration range: 305 – 18,542 m/s
- Dual element probe with recalibration on different materials
- High-speed Scan mode
- Differential mode (deviation from a reference value)
- Hi/Lo threshold alarm
- Powered by 2 AA batteries (up to 45 h with alkalines)
- Weight 312 g, operating temperature from -30 to +75 °C
Need help choosing the right product?
What the ZX-3 does not have compared with the higher models: it has no data logger, it does not display the A-Scan waveform and it does not support Echo-Echo mode for measurement through coatings.
What the Dakota CMX1-DL is
The Dakota CMX1-DL is a corrosion gauge with an A-Scan display, that is the graphical representation of the ultrasonic waveform alongside the numerical value. The main features from the official catalogue are:
- Multiple measurement modes: Pulse-Echo (PE), Echo-Echo (EE), Pulse-Echo Temperature/Comp Mode (PETP), Coating Only (CT), Pulse-Echo Coating (PECT)
- High-speed scan mode: up to 250 readings per second (CMX1-DL)
- 4 GB internal memory for data logging with download to the DakMaster™ software
- Differential mode and minimum thickness alarm
- 3 fully adjustable gates (start, stop, width, threshold)
- Adjustable damping (50 – 1500 ohm)
When the ZX-3 is enough
The Dakota ZX-3 fully covers the applications that call for:
- Quick thickness measurements on homogeneous, uncoated material
- Repetitive checks in production or in the workshop
- Reading a numerical value with no need for storage
- Operators who do not need a graphical interpretation of the signal
- First-level maintenance on simple metal structures
When moving up to the CMX1-DL is essential
Moving up to the Dakota CMX1-DL becomes necessary in the following scenarios:
- Signal interpretation: when the numerical reading alone is not enough and you need to see the A-Scan waveform to validate the quality of the measurement (double echoes, insufficient coupling, intermediate echoes)
- Coated surfaces: Echo-Echo mode and the Coating Mode variants make it possible to measure the metal thickness correctly, either excluding the coating or quantifying it separately
- Inspection of pitting and localised defects: the A-Scan makes it possible to identify echoes from point defects that a numerical display cannot bring out
- Reporting and traceability: the 4 GB memory and DakMaster™ integration make it possible to manage coded inspections with sampling plans and historical storage
- Inspections compliant with standards: API 570, API 653 and equivalent procedures require data storage that the ZX-3 does not support
Summary comparison table
| Feature | Dakota ZX-3 | Dakota CMX1-DL |
|---|---|---|
| Display type | Numerical digits | Graphical A-Scan + digits |
| PE range | 0.63 – 914.4 mm | Wide range (see product data sheet) |
| Measurement modes | Pulse-Echo | PE, EE, PETP, CT, PECT |
| Measurement on coated surfaces | No | Yes (EE and Coating modes) |
| Differential mode | Yes | Yes |
| Threshold alarm | Yes | Yes |
| Scan mode | High-speed | Up to 250 readings/sec |
| Data logger | No | Yes (4 GB) |
| DakMaster™ integration | No | Yes |
If You are unsure between a basic gauge and a more advanced instrument, our technical office can help You assess Your use case in practical terms. Contact us for dedicated advice.