When you're shopping for electrical testers, an insulation resistance tester is a specialized purchase. You're often choosing between a new, calibrated instrument and a used, more affordable one. The Fluke 1507 and Amprobe MegaTest 1 AMB-45 both fit the megohmmeter category, but they come with very different prices and conditions.
Quick verdict
The Fluke 1507 is the pick if you want a new-condition insulation tester with a broad test voltage range, live circuit detection, and NIST-traceable calibration. The Amprobe AMB-45 is the value choice, bundling a case and leads with true RMS and extra measurement functions.
Compared at a glance
| Fluke 1507 | Amprobe AMB-45 | |
|---|---|---|
| Price | $611.00 | $399.97 |
| Condition | New open box | Used |
| Highlighted specs | 50, 100, 250, 500, 1000 V insulation test voltage; 0.01 MΩ to 10 GΩ range; live circuit detection; auto-discharge; measures resistance and AC/DC voltage | True RMS; measures resistance, frequency, temperature, voltage, capacitance; auto power off; over range protection |
| Included | NIST traceable calibration | Carrying pouch, test leads, cable, manual, CD |
Where the Fluke 1507 wins
The Fluke 1507 provides insulation test voltages from 50 V to 1000 V, an insulation resistance range from 0.01 MΩ to 10 GΩ, live circuit detection, and auto-discharge. It's in new open box condition and includes NIST-traceable calibration. These features make it a strong choice for insulation-focused work where consistent test settings and user protection matter.
Where the Amprobe AMB-45 wins
The Amprobe AMB-45 comes with its original carrying pouch, test leads, an extra cable, manual, and CD. It delivers true RMS, auto power off, over range protection, and the ability to measure resistance, frequency, temperature, voltage, and capacitance. That broader measurement set makes it a more versatile handheld for technicians who don't need insulation testing on every job.
Product notes
Fluke 1507 Insulation Resistance Tester
The Fluke 1507 is built for insulation testing with a spec sheet that lists five insulation test voltages and a resistance range that goes beyond traditional multimeters. It also measures low resistance and AC/DC voltage, so it covers basic electrical checks too. The live circuit detection and auto-discharge features are practical safety aids when you're working around capacitive circuits. The unit is listed as new in open box, and it comes with NIST-traceable calibration, which is a valuable addition for those who need documented measurement traceability. The trade-off is the $611 price, which is more than $200 above the Amprobe. If your primary work is insulation resistance testing and you want a new-condition meter with calibration, the Fluke is easy to justify.
Amprobe MegaTest 1 AMB-45 Insulation Resistance Tester Megohmmeter
The Amprobe AMB-45 offers a lower entry point at $399.97. It's described as a used handheld tester in good cosmetic and working condition, with a crisp screen and minimal signs of handling. It arrives with its original carrying pouch, test leads, an additional cable, manual, and CD, so you have what you need to start testing. The AMB-45 goes beyond insulation resistance by also measuring frequency, temperature, voltage, and capacitance, and it includes true RMS. Auto power off and over range protection round out the feature set. The main limitation is its used condition; you're getting a pre-owned instrument rather than a new one. For budget-conscious technicians who want a versatile electrical tester, the Amprobe is a practical pick.
Final choice by use case
Choose the Fluke 1507 when your focus is insulation resistance testing, especially if you need multiple test voltages, live circuit detection, auto-discharge, and NIST-traceable calibration on a new instrument. Choose the Amprobe AMB-45 when you want to spend less and prefer a single handheld that also measures voltage, capacitance, frequency, and temperature-and you're comfortable with a used unit.
