PosiTector DPM L+

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.

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.

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.

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.

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.

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 (122° F).

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.

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