When you're shopping for calibration equipment standards for a test bench, you often have to choose between a lower-priced unit that powers on and a more specialized temperature calibrator sold as-is for parts or repair. That's the exact fork in the road here: the B&K 750 Test Equipment Calibrator Null Indicator and the Thermo Electric 311600 Temperature Calibrator Indicator Digi-Mite. Both are used units with meaningful caveats, so the right pick depends on what you need after it arrives.
Quick verdict
The B&K 750 is the budget-oriented choice at $49.00, and it gives you a used null indicator that powers on. The Thermo Electric 311600 Digi-Mite is the pricier option at $98.50 and suits a repair project rather than immediate use. If you want a lower-cost unit to inspect and verify yourself, start with the B&K. If you specifically need a Digi-Mite for restoration or parts, the Thermo Electric is the one to watch.
Side-by-side comparison
| Product | Listed Price | Price Bar | Condition | Best For |
|---|---|---|---|---|
| B&K 750 Test Equipment Calibrator Null Indicator | POWERS ON UNTESTED | $49.00 | Used | Null-indicator work on a budget | |
| Thermo Electric 311600 Temperature Calibrator Indicator Digi-Mite [A1B1 | $98.50 | For parts or not working | Digi-Mite projects or parts |
Where each product wins
- The B&K 750 wins for a buyer who wants the lower-priced calibrator and is okay with its used, untested condition. It lists wired connectivity, which fits a stationary bench setup.
- The Thermo Electric 311600 wins if your work is specifically around temperature calibration and you want the Digi-Mite model as a project unit. The condition label is the trade-off: restoration or spare parts rather than plug-and-play use.
Product notes
B&K 750 Test Equipment Calibrator Null Indicator | POWERS ON UNTESTED
The B&K 750 offers a used, wired null indicator with a blue housing and visible scratches and imperfections, yet it is described as being in good condition for its age. The defining detail is that it powers on: the listing says the light comes on when plugged in, but no other tests have been performed. That makes it a solid candidate if you want a vintage calibrator to inspect, wire into a bench setup, or use as a starting point for your own verification. The limitation is exactly that untested status. You have no confirmation that the calibrator's function is accurate, so you need to be ready to test it yourself. The visible wear also means this is not a clean showpiece.
Thermo Electric 311600 Temperature Calibrator Indicator Digi-Mite [A1B1
The Thermo Electric 311600 fills a different gap: it is a temperature calibrator indicator built around the Digi-Mite name, and it comes from a closed plant's parts crib. It is listed for parts or not working, which makes it a project-oriented purchase rather than a ready-to-use instrument. The listing notes that they don't know how to test it, so any expectation of immediate calibration accuracy is off the table. If your goal is to restore a Digi-Mite 311600, harvest components, or attempt a repair, it gives you a specific model to work from. The listing includes the part number 311600 and indicates the country of origin as China. For someone who needs a confirmed working calibrator right away, this unit is not the right fit.
Final choice by use case
For a lower-cost null indicator you're willing to verify yourself, the B&K 750 is the practical pick. For a calibration project built around the Digi-Mite model, especially if you don't mind condition issues, the Thermo Electric 311600 is the one to choose. In short, buy the B&K 750 if you want to start working with the unit now; buy the Thermo Electric if you're prepared to repair or part it out.
