Fluke 15B+: What the Fluke Documents State

Quick answer

• Display: 4000 counts, updating three times per second, per Fluke’s datasheet.
• Safety: IEC 61010-1 and IEC 61010-2-030, CAT III 600 V, Pollution Degree 2. The datasheet also lists a maximum voltage of 1000 V between any terminal and earth ground.
• Power: two AA batteries (NEDA 15A, IEC LR6), with a stated battery life of 500 hours minimum.
• Current protection: a 440 mA, 1000 V fast fuse and an 11 A, 1000 V fast fuse, both Fluke-specified parts.

What the meter measures

The datasheet lists AC and DC voltage, AC and DC current, resistance, capacitance, frequency, duty cycle and continuity. Voltage ranges run from millivolts up to the 1000 V input. Current ranges include a 400 mA range and a 10 A range, and the datasheet lists accuracy figures for each.

The accuracy figures are written as a percentage of the reading plus a number of least significant digits. The datasheet gives the figure for one year after calibration, between 18 °C and 28 °C and at 0% to 75% relative humidity. Use the accuracy line for the range you need, not a single headline number. The datasheet also notes that AC, frequency and duty-cycle figures apply from 1% to 100% of range, and that inputs below 1% of range are not specified.

Input impedance is also stated. The datasheet lists DC volts at greater than 10 MΩ and less than 100 pF. A high input impedance means the meter draws very little current from the circuit under test, which helps avoid loading a sensitive circuit. Read the datasheet’s common-mode rejection line if you measure noisy circuits.

Safety rating and what it means

Work on mains circuits can kill. The category rating tells you the highest transient voltage and voltage to earth the meter is designed for in a given category. Fluke states that the 15B+ is rated CAT III 600 V under IEC 61010-2-030, with Pollution Degree 2. The datasheet also lists a 1000 V maximum voltage between any terminal and earth ground.

Those numbers describe the meter’s design limits. They do not mean the meter is safe on any circuit up to those values. Match the category to the point where you are working. If you are unsure whether a panel, service entrance or outlet is in a category this meter covers, stop and call a licensed electrician. Panel and service work belongs to a licensed electrician.

The users manual includes a warning about overload. It says that when the meter shows a hazardous voltage of 30 V or more, or a voltage overload (OL), the hazardous voltage alert LED lights. Treat that LED as a stop signal, not a reading.

Fuses, battery and build

The datasheet names two fuses. One protects the low-current input with a 440 mA, 1000 V fast fuse. The other protects the high-current input with an 11 A, 1000 V fast fuse. Both are listed as Fluke-specified parts. Use only the replacement fuses Fluke specifies, because a fuse with the wrong rating can leave the input unprotected.

The meter takes two AA batteries. The datasheet lists a battery life of 500 hours minimum, and it notes about 50 hours in LED test mode without load. Replace the batteries before the meter shows a low-battery indication, and close the battery cover before use.

The datasheet gives the weight as 455 g, the size as 183 × 91 × 49.5 mm and the IP rating as IP40. It gives an operating temperature of 0 °C to 40 °C and a storage temperature of -30 °C to 60 °C. Those figures matter if you work outdoors in cold or hot conditions, or if you store the meter in a van.

Skip if

• You need a meter for automotive or fuel-system work where the category rating or the input range is a concern. Check the category needed for your circuit before you buy.
• You need a clamp for current. The sources describe the 15B+ as a multimeter with test-lead inputs and do not describe a clamp accessory for it.
• You need a meter with a stated true-RMS function on the bench. The datasheet and manual we opened do not state true-RMS measurement for the 15B+. Check the function list in the manual before you buy if that matters for your work.

How we chose

This article covers one model. It uses three documents opened on 27 October 2026: the 15B+/17B+ datasheet, the 15B+/17B+/18B+ users manual and the 15B+ product page. The criteria are the figures and safety statements those documents publish. The article does not rank the 15B+ against other meters, and it does not describe any test by the author. Where two sources differ, this article says so.

What we could not verify

• The sources we opened do not state whether the 15B+ measures true RMS. Do not assume that it does.
• The datasheet, the manual and the product page each describe the 15B+ as CAT III 600 V. The 1000 V figure is given as a maximum voltage between any terminal and earth ground, which is a different limit from the category rating. Ask Fluke or the manual’s safety section if you need that difference explained for your work.
• The sources do not state a warranty length, a country-specific price or a shipping time.
• The sources do not give a list of accessories, such as test leads, that come with the meter. Check the box contents before you buy.

FAQ

How many counts does the Fluke 15B+ show?

Fluke’s datasheet lists a 4000-count display that updates three times per second.

What CAT rating does the 15B+ have?

The datasheet and product page both list IEC 61010-2-030, CAT III 600 V, Pollution Degree 2. The datasheet also gives a 1000 V maximum voltage between any terminal and earth ground.

What batteries does it use?

Two AA batteries, NEDA 15A and IEC LR6, according to the datasheet. The stated battery life is 500 hours minimum.

What fuses protect the current inputs?

A 440 mA, 1000 V fast fuse on the low-current input, and an 11 A, 1000 V fast fuse on the high-current input. Both are Fluke-specified parts.

Is the 15B+ the same as the 17B+?

Fluke’s datasheet covers both models in one document. The datasheet attributes a temperature probe, overload protection and an over-voltage indicator to the 17B+, not the 15B+. Compare the two model pages before you choose.

What is the IP rating?

IP40, according to the datasheet.

Bottom line

The Fluke 15B+ is a battery-powered digital multimeter with a 4000-count display and a published CAT III 600 V rating. It uses AA batteries and two Fluke-specified fuses. Before you buy, confirm the category you will work in, whether you need a true-RMS function, and whether you need a clamp.

Related guides

• Best Fluke 1507 Test Leads: What to Check Before You Buy covers the leads and their ratings, which matter for any Fluke meter.
• Fluke Multimeter Lineup: 7 Meters Compared by Stated Function compares Fluke meters by the functions their makers state.
• Best Fluke 117 Case: 4 Hard Cases Compared covers cases for a Fluke meter kit.

Sources

• Fluke Corporation, “TECHNICAL DATA Fluke 15B+/17B+ Digital Multimeters”, https://media.fluke.com/13f4f547-c677-44dc-af90-b1380151359c_original%20file.pdf (opened 2026-10-27)
• Fluke Corporation, “15B+/17B+/18B+ Digital Multimeters Users Manual”, https://media.fluke.com/f8ca9de4-481a-4125-8a46-b2d9006f431f_original%20file.pdf (opened 2026-10-27)
• Fluke Corporation, “Fluke 15B+ Digital Multimeter” product page, https://www.fluke.com/en-us/product/electrical-testing/digital-multimeters/fluke-15b-plus (opened 2026-10-27)