Between a handheld digital caliper and a pressure switch for a coordinate measuring machine, the right choice depends entirely on the inspection job at your bench. The Mitutoyo 300mm/12" Absolute Digital Digimatic Caliper is a brand-new measuring tool that reads parts directly. The Mitutoyo BHN506 Pressure Switch is a CMM component that safeguards the air-bearing system from pressure loss. This head-to-head looks at what each one does, what you pay, and when you would buy it.
Quick verdict: If you need to measure parts at your workstation, buy the caliper. If you are servicing a CMM and need the air-pressure safety sensor that keeps the machine from crashing, the BHN506 is the part to source. They aren't interchangeable, but for a shop that does both inspection and CMM maintenance, these are two sensible ways to spend a metrology budget.
| Mitutoyo Absolute Digital Caliper | Mitutoyo BHN506 Pressure Switch | |
|---|---|---|
| Price | $89.10 | $399.00 |
| Condition | New | Used |
| Primary role | Direct part measurement | CMM air-pressure safety trigger |
| Measurement range | 0 to 12 in | - |
| Accuracy | ±0.001 in (±0.02 mm) | - |
| Output / technology | Absolute encoder, LCD, SPC data output | Adjustable Sanwa Denki SPS-8T pressure switch |
| Origin | Japan | Japan |
Where the caliper wins: The caliper is the everyday measuring tool. The absolute encoder means it holds its zero even after you power it off, and the digital LCD makes readings quick. The SPC data output is a nice bridge to quality-control documentation. It also delivers Mitutoyo measurement capability in a familiar handheld format.
Where the pressure switch wins: The pressure switch is not a measuring instrument, but it is a critical safety part for a CMM. If air pressure to the air bearings or counterbalance drops, this Sanwa Denki SPS-8T adjustable switch triggers an interlock or fault signal before the machine can damage its guideways. If you are repairing or maintaining a CMM, this is the authentic component that keeps the machine's safety system intact.
Mitutoyo 300mm/12" Absolute Digital Digimatic Vernier Caliper
This new digital caliper is a practical choice for anyone who measures parts directly on the shop floor. It reads from 0 to 12 inches and maintains ±0.001-inch accuracy, which is tight enough for many inspection tasks. The absolute encoder setup means you don't have to reset the origin each time, and the LCD handles the readout clearly. You can switch between metric and inch readings, and the SPC data output lets you send results to quality documentation. The stainless steel body is durable for repeated use. One limitation to keep in mind: this is a handheld instrument, so it won't help you maintain a CMM, and its 12-inch measuring range caps the size of parts you can check. If your work stays within that range, this is a strong $89.10 investment for day-to-day inspection.
Mitutoyo BHN506 Pressure Switch with Sanwa Denki SPS-8T
If your job involves keeping a coordinate measuring machine running, this BHN506 pressure switch is the component that guards the air-bearing system. It is an adjustable Sanwa Denki SPS-8T switch manufactured in Japan, and it is designed to monitor the air pressure that supports the CMM's sensitive guideways. When pressure falls below the optimal threshold, the switch signals an interlock or fault, protecting the machine from potential damage. That makes it a necessary replacement part during CMM service. The trade-off is that it is a used component, and at $399 it costs noticeably more than a handheld caliper. It also has no measuring function, so it is not an alternative for direct part measurement. Buy it when you are repairing or maintaining a CMM, not when you need to read dimensions.
Final choice by use case:
- For daily dimensional measurement of parts: choose the Mitutoyo Absolute Digital Caliper.
- For CMM air-pressure safety or repair: choose the Mitutoyo BHN506 Pressure Switch.
- If you need both capabilities in the shop, the two purchases address completely different needs, so budget for both if the work demands it.
