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Delmhorst Instrument Co. BD-2100 Moisture Meter

The Delmhorst Instrument Co. BD-2100 is a digital 2-in-1 pin meter (integral pins, hammer probe) that uses resistance technology to measure moisture in wood, gypsum (drywall) and other non-wood building materials such as concrete, plaster and EIFS.

. It can accommodate an array of optional electrodes and a slide hammer (hammer probe) to assist one in measuring surface or near surface MC percentages on several types of materials.

This review was based on using this meter with “Integral Pins” A drawback for this meter is that one must look up a species adjustment from the tables provided for every measurement which is time consuming.  On the other hand having the ability to store 100 readings in memory and having recall options as well as the LED lights which indicate general moisture conditions with the digital display is a plus for this meter.

Based on these factors and its excellent performance scores, this meter is worth purchasing.

Please see the separate review using the BD-2100 with the “Hammer Probe” attachment.

Overall Rating: 3.95 out of 5.0  


  • Easy to view L.E.D. lights
  • 100 readings in memory
  • An audible alarm with preset able set point
  • The manual lists key factors to consider when testing various materials


  • Integral pins were not durable, broke easily
  • Readings only display for 2 seconds-no hold button
  • low battery indication, not available
  • Lowest reading in memory will not be displayed
  • Only 1-year warranty

Accuracy Test: Score 4.30 Out Of 5.0

This meter does not read accurately down to its stated minimal 6%MC and accuracy above 21% MC drops off, resulting in inconsistent readings.

Surface Moisture Test: Score 1.0 Out Of 5.0

Surface moisture had an extreme effect on this meter’s readings.

The surface moisture test showed an increase of 14% in MC readings from the baseline. While a difference of only a few percent MC from baseline might be acceptable, an increase of 14% indicates this meter may not be accurate while in the presence of surface moisture.

If one performs this test the same way that we did, then one can observe similar results.

Meter Temperature Test: Score 4.50 Out Of 5.0

Meter temperature had a small effect on this meter’s readings.

A low meter temperature of 33 degrees while in the presence of a low MC sample barely decreased when compared to a meter temperature at 70 degrees. While in the presence of high MC, the reading dropped by 1.1%.

A high meter temperature of 110 degrees in the presence of low MC decreased the reading by 1.3% also compared to a meter temperature of 70 degrees. While in the presence of high MC, the reading decreased by 1.6%.

Wood Temperature Test: Score 4.50 Out Of 5.0

Wood temperature also had a small effect on this meter’s readings.

A low wood temperature, with the low MC sample increased the reading by 1.3% when compared to room temperature, while in the presence of high MC, the reading barely decreased.

A high wood temperature while in the presence of low MC barely decreased when compared to room temperature. While in the presence of high MC the reading decreased by 1.2%

Drift Test: Score 3.0 Out Of 5.0

Test indicated that readings drifted significantly.

Reading repeatability: Score 4.0 out Of 5.0

Delmhorst BD-2100 meter readings were mostly repeatable.

Subjective Testing:  overall score 3.80 out of 5.0

Ease of use: Score 4.0 out Of 5.0

Simple to operate, species adjustment required and temperature correction is needed if ambient temperature is below 50 or above 90 degrees

100 readings can be stored in memory and must be cleared when maximum is reached. With only 15 measurements in storage one can see the highest and the average of those readings. No provision has been made to display the lowest reading in memory. The LED lights aid in quickly identifying moisture range for each reading especially while testing in low light environments.  

Quality: Score 4.0 Out Of 5.0

Manufactured in the United States, this pin meter is constructed of impact resistant plastic and comes in a sturdy plastic carrying case.  The non- insulated meter pins, however, are not very durable and broke more frequently than expected.

Comfort: Score 4.0 Out Of 5.0

Meter is easy to hold and fits well in one’s hand. It would have been nice if this meter had a carrying bag that could be clipped to one’s belt.

Price: Score 2.0 Out Of 5.0

The price point of $340 is mostly fair when taking into consideration that the meter performed better than average throughout rigorous testing, however there are some limitations to both its features and functionality.

Versatility: Score 4.0 Out Of 5.0

The BD-2100 can measure moisture in a variety of materials including wood, concrete, stucco, gypsum/drywall, plaster and external Insulation Finishing Systems-EIFS and other masonry.

We only perform our tests on various species of wood, so we cannot comment on reading accuracy for those other non-wood materials.

Range: Score 4.0 out Of 5.0

Manufacturer’s stated range: 6%-40%

Accuracy Test indicates range limitations.

Delmhorst indicates that any readings over the fiber saturation point of 30% are less accurate.

Features: Score 4.0 out of 5.0

  • 4 function buttons: read (MC percentage for wood /relative moisture value for other non-wood materials), calibration check (when pressed with read button checks calibration), number scale (sets display scale #1-wood, #2-reference scale #3-gypsum, drywall), set point(programs the set point)
  • Display in 0.1% precision
  • Species adjustment is necessary, except for

construction grade lumber which can be taken at face value with out any correction.

  • No temperature compensation needed if ambient temperature is between 50-90 degrees F
  • 100 readings in memory, when max is reached the memory must be cleared
  • Highest and average of readings in memory will display, lowest reading displayed is not an option
  • Reading displays for only 2 seconds
  • Readings below 6% will display as 5.8% and over 40% will be displayed as a flashing 40.0%. These readings will not be added to stored readings.
  • LED lights indicate general moisture condition:

For wood-green (6-15%), yellow (15-17%), red (greater than 17%)

For gypsum:  green (0-0.5%), yellow (0.5-1.0%), red (greater than 1.0%)

For reference scale readings:  green (0-85), yellow (85-95), red (greater than 95)

  • Buzzer alerts if the meter reads higher than the selected value
  • Integral pins are 5/16” and are not very durable
  • Meter settings must be reset after battery has been replaced
  • Calibration verification (internal-pressing calibration check button)
  • Only 1-year warranty

This meter does not have the following feature which would greatly enhance the user experience:

  • Hold button to freeze readings

Ruggedness: Score 4.0 Out Of 5.0

The Delmhorst BD-2100 passed our standardized drop test, falling 4 feet onto concrete. The meter was able to take readings after the test occurred, although a calibration check is recommended. On this model, the screen will read 12% if properly calibrated. If the readout is different then one should change the battery as the voltage might be too low and then check calibration again.  If at that time 12% does not display then the meter must be sent back to Delmhorst to be officially recalibrated.

Customer Service: Score 4.0 Out Of 5.0

The representative was polite and helpful providing information about the meter’s warranty (1 year) and need for calibration (check annually).

When meter is out of warranty:

  • Customer pays for round-trip shipping when repairs are needed
  • Minimum repair charge is $95 in addition if meter case is cracked the technician will determine what that particular repair charge will be.
  • Recalibration cost of $100 is considered high and an additional $15 is charged for the certificate.
  • Repair turn-around time is 10 days but customer can arrange for faster service at a premium.

Manual was easy to read and provided many useful instructions when measuring different types of materials.  Contact information was up-to-date.