503-342-0025 info@moisturemeter.com

We take pride in our testing standards. Read more about that here.

Delmhorst BD2100 Hammer
Our Score:
Delmhorst BD2100 Hammer at a glance

The Delmhorst BD-2100 comes with a slide hammer that uses resistance technology for measuring moisture content (MC) at various depths in wood and other building materials.

The meter itself features three scales for use with wood, plastic/concrete, and gypsum, along with color-coded indicators of moisture content for each. One has to correct for species and temperature using tables in the manual, which is somewhat inconvenient.

The slide hammer accessory comes with durable pins and scored higher than most other meters in our tests for accuracy.

Our assessment is that this is a useful accessory for the BD-2100.


  • Provides higher accuracy than most of the wood meters we tested.
  • Very durable pins.
  • Designed for use with many types of building materials.
  • Built-in calibration check.
  • Capable of storing and averaging up to 100 readings.


  • Hand or finger may get pinched when operating.
  • Temperature and species adjustments require using a table.
  • Range does not extend below 6%.
Delmhorst BD-2100 Moisture Meter Review

Delmorst BD2100 Moisture Meter

We put the 2100 through our battery of rigorous testing. Get the answers you need before you buy.

Objective Evaluation – Score 4.2 out of 5.0

Objective test summary results for the Delmhorst BD-2100 slide hammer, achieving objective score of 84%

Accuracy – 4.6 out of 5.0

The hammer probe is accurate in the 7% to 18% range when compared to ASTM-4442 oven dry standards. It is not quite as accurate at higher MC levels. The BD-2100 does not have the capability to read below 6% and instead reads -5.8%.


Learn about our accuracy test procedures

Surface Moisture – 1.0 out of 5.0

This meter’s slide hammer probe showed a 4.6% change in the reading in the presence of surface moisture. This indicates that operating this meter’s hammer probe in high humidity environments where condensation may form on the surface could lead to questionable readings.


Learn about our surface moisture test procedures

Meter Temperature – 5.0 out of 5.0

Meter temperature had a minimal effect on this hammer probe’s readings.

A low meter temperature of 34.8° F in the presence of low MC increased the reading by only 0.2% from a room temperature of 70.5° F, while in the presence of high MC, it decreased by 0.1%.

A high meter temperature of 110° F decreased the reading by only 0.1% in the presence of low MC and decreased it by 0.6% in the presence of high MC.

Bar chart showing meter temp had a minimal effect on the Delmhorst BD-2100 slide hammer's readings.

Learn about our meter temperature test procedures

Wood Temperature – 4.0 out of 5.0

Wood temperature had a small effect on this hammer probe’s readings.

A low wood temperature in the presence of low MC increased the reading by 1% while in the presence of high MC the reading dropped 1.5%.

A high wood temperature in the presence of low MC decreased the reading less than 0.9%, but in the presence of high MC, the reading dropped 2.1%.

Bar chart showing wood temperature had a small effect on the Delmhorst BD-2100 slide hammer's readings.

Learn about our wood temperature test procedures

Reading Repeatability – 5.0 out of 5.0

The slide hammer probe’s readings were highly repeatable.


Learn about our repeatability testing procedures

Drift – 4.0 out of 5.0

Readings with this meter must be taken immediately after pin insertion because the meter displays the moisture content for only 2 seconds unless the button is held down. Even then, this meter’s readings showed some drift after 3 seconds. When one needs more than 3 seconds to obtain the reading, this may lead to inaccurate readings.

Bar chart showing the Delmhorst BD-21—Slide Hammer may return inaccurate readings if held longer than 3 seconds

Cable Interference – 5.0 out of 5.0

The slide hammer probe had little cable interference. All readings returned to normal when the interference was removed.

Bar chart showing the Delmhorst BD-2100 Slide Hammerhead little cable interference

Learn about our cable interference and drift testing procedures

Subjective Evaluation – Overall Score 3.7 out of 5.0

Subjective test summary results for the Delmhorst BD-2100 Slide Hammer, earning a subjective score of 73%

Learn about our subjective testing procedures

Ease of Use – 3.5 out of 5.0

The slide hammer is mostly easy to use. Little use of the manual is needed except for using the tables to adjust for species and wood temperature.

Quality – 5.0 out of 5.0

Both the slide hammer and the meter are constructed of durable materials and are unlikely to break or malfunction with normal use. We also found the supplied pins for the slide hammer to be very durable during testing, with no breakage or bending.

Comfort – 4.5 out of 5.0

One has to be careful operating this slide hammer probe to avoid a pinched hand or finger. With an ergonomically-designed shape, the meter itself fits nicely in one’s hand. It is not compact enough to fit easily into a shirt pocket, but it does come with a hard case to protect the meter when transporting it from one job site to the next.

Versatility – 1.0 out of 5.0

This is a single-mode meter (pin), which is typical. One must use the species correction table in the manual to adjust for wood species. Capable of being used with a variety of building materials. The insulated pins for the slide hammer probe can be driven to the desired measurement depth.

Range 3.7 out of 5.0

This meter reads from 6% to 40% and is not capable of taking measurements when the moisture content is below 6%.

Features 3.5 out of 5.0

Readings precise to the nearest 0.1%. Notable features include the ability to store and average up to 100 readings, a built-in calibration check, an audible alarm to alert the user that the reading exceeds a selected value and three scales for use with different building materials.

Customer Service – 4.5 out of 5.0

Delmhorst customer service was knowledgeable, helpful, and polite. The representative was able to answer all the basic questions about repairs, returns, etc. Fast response to both telephone and email inquiries. Manual available online.

Warranty and repair information:

  • One-year warranty for all Delmhorst meters; 90-day warranty for electrode accessories.
  • The meter must be physically inspected before the actual repair cost can be determined.
  • 3-5 business day turnaround on repairs.

Our review is based on Moisture Meter Experts independent evaluation of the meter, which was purchased by Moisture Meter Experts or provided free of charge by the manufacturer. By purchasing this meter through the links above, Moisture Meter Experts may be compensated either by your purchase directly from Moisture Meter Experts or from commissions from an affiliate. View our Review Procedures section to learn more about our proprietary evaluation procedure and expertise in the field of moisture meters.