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DPM-L Positector® Dew Point Meter Logger

Made in USA-Defelsko
PosiTector DPM L Dew Point Meter Logger
Click images to enlarge.
The PosiTector DPM L Dew Point Meter Logger magnetically attaches to steel structures to measure and record climatic conditions at user-selected time intervals independently for up to 200 days. Stored datasets can be viewed or downloaded using a PosiTector Advanced gage body (S/N 784000+) or Apple/Android smart device.

At each interval, the PosiTector DPM L stores relative humidity, air temperature, surface temperature, dew point temperature, the difference between surface and dew point temperatures, and wet bulb temperature. Ideal for surface preparation as required by ISO 8502-4.

Conforms to ISO 8502-4, BS 7079-B4, ASTM D3276, IMO PSPC, SSPC-PA7 and US Navy NSI 009-32.


  • Attaches to steel structures to measure and record environmental parameters independently for up to 200 days. Stored datasets can be downloaded using a PosiTector Advanced gage body or Apple/Android smart device.
  • Records parameters at user selected intervals from 1 min. to 8 hrs.
  • Environmentally sealed enclosure – weatherproof, dustproof, and shockproof — meets or exceeds IP65
  • Fast response precision sensors provide accurate, repeatable readings
  • Internal memory storage of 10,000 datasets (60,000 readings)
  • Kensington Security Slot for anti-theft protection. Kensington Lock sold separately.
  • Uses common lithium coin cell batteries (CR2032)
  • Every stored dataset is date and time stamped
  • Certificate of Calibration showing traceability to NIST included
  • Conforms to national and international standards including ISO and ASTM
  • Two year warranty

Measuring Range

DPM-L Specs


SizeØ50 mm x 38 mm (Ø2" w x 1.5" h)
Weight50 g (1.8 oz.) without battery
Operating Range-10° to 60° C
Memory10,000 datasets
@ 5 min interval = 34 days
@ 10 min interval = 68 days
Logging Measurement IntervalAdjustable from 1 min – 8 hours
IP Rating65
Battery Life@ 5 min interval = 120 days
@ 1 hour interval = 200 days

Related Products

Click image for more info
Positector® Environment Meter / Dew Point Meter

Data Output

DPML OutputFor use with the PosiTector App and PosiTector Advanced
  • Display and record climatic parameters from remote (wireless) PosiTector DPM L probes
  • Automatically download readings once connected via Bluetooth 4.0 Technology (Bluetooth Smart)
  • View live measurement data on screen
  • Alarms indicate when climate conditions exceed user-selectable parameters
  • Smart TrendTM indicators identify rising falling or stable readings
  • Easily create reports and manage data with PosiSoft software
PosiTector App
  • An easy-to-use mobile app (iOS/Android) that wirelessly connects to PosiTector DPM L Smart Probes.
  • Automatically generate user-formatted reports and share via email, text, cloud storage services like Dropbox, and more
PosiTector Advanced
  • Storage of 100,000 datasets in up to 1,000 batches
  • Onscreen graphing of measurement data
  • Includes the entire PosiSoft Suite of solutions for analyzing and reporting data
  • View and print readings and graphs using universal PC/Mac web browsers and file explorers

What's Included

ALL GAGES COME COMPLETE with air/surface temperature sensors, RH sensor, two CR2032 coin cell batteries, instructions, Long Form Certificate of Calibration traceable to NIST, storage container, and two year warranty.

DPML Frequently Asked Questions

Do your instruments require any formal training for use? Do you offer ‘demo’ models?
No. Our instruments are designed for simple operation, feature easy-to-use menus, both full and quick instruction manuals, and helpful videos. In lieu of demonstration models, we provide unlimited technical support via telephone and/or email, and a limited 30-day money back guarantee.

How often should the PosiTector probe be recalibrated?
PosiTector probes include a Certificate of Calibration with no expiry or end date. They have no shelf life, therefore the length of time in the field is not a good indicator for recalibration intervals. Many organizations with quality programs and recertification programs require annual recalibrations, and this is a good starting point for most users. DeFelsko recommends that customers establish calibration intervals based upon their own experience and work environment. Based on our product knowledge, data and customer feedback, a one year calibration interval from the date the instrument was placed in service is a good starting point.

Is the PosiTector DPM L calibrated at the factory?
The PosiTector DPM L arrives fully calibrated and ready to measure. A Long-Form Certificate of Calibration traceable to NIST or PTB is included, which documents actual readings taken by your instrument at our calibration laboratory on standards traceable to a national metrology institute. Beware of ‘Certificates’ or ‘Certificates of Conformance’ offered by competitors. These typically do not include actual instrument readings, and are often insufficient to meet common quality requirements.

Does the PosiTector DPM L provide a wet-bulb temperature measurement?
Yes. When combined with either a PosiTector Advanced gage body or iOS/Android smart device, the DPM L will indicate a wet-bulb temperature measurement.

Is the PosiTector DPM L suitable for applications with low or negative dew point temperatures?
The PosiTector DPM L provides accurate dew point readings (±3° C) down to -40° C.

Dew point is a calculated value, based on temperature and humidity. At low negative dew point temperatures, the calculation is highly dependent on relative humidity and changes of ±3% RH (the tolerance of the PosiTector DPM’s humidity sensor) can have a significant impact on the dew point temperature.

The Dew Point (Td) Accuracy page details the accuracy of the calculated dew point temperature based on the measured temperature and humidity.

How long does it take the logger to acclimate, and provide accurate readings in a new environment?
The PosiTector DPM L, like other electronic dew point meters, requires adequate time to acclimate to its operating environment. When moving between similar environments, the instrument will stabilize in a matter of seconds. However, when moving between environmental extremes (like between a dry, air conditioned vehicle and the warm, humid outdoors) it can take up to 30 minutes for readings to stabilize.

If left in a dry environment for an extended period of time, this stabilization process may take longer. To restore the original response time, wrap the sensor in a damp cloth overnight.

Is the PosiTector DPM L suitable for logging temperatures inside an oven?
No. We do not recommend our PosiTector DPM L for operation in an oven. Delicate internal components and assembly materials are prone to premature damage when subjected to prolonged use in a closed environment with temperatures greater than approximately 50° C.

How long does the battery last on a PosiTector DPM L?
Depending on the logging interval, the battery on a PosiTector DPM L can last several months. For example, at 5 minute intervals the logger will last 120 days. At 1 hour intervals, the PosiTector DPM L will last 200 days. The stated battery life is for unattended logging. Battery life is reduced while connected to the PosiTector app or instrument.

What is the operating temperature range of the PosiTector DPM L
The operating temperature range of the PosiTector DPM L is -10 to 60° C (14 to 140° F).


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Item Description Price
PosiTector Dew Point Meter Logger
Kensington Lock for DPML
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