DeFelsko PosiTector DPM Dew Point Meter

Dew point and climate readings before you blast or coat

The DeFelsko PosiTector DPM is a dew point meter that measures and records relative humidity, air temperature, surface temperature, dew point temperature, the difference between surface and dew point temperature and, on one probe, wind speed. All readings update continuously on the display, so the inspector does not need psychrometric tables or a slide rule. Alarms indicate when climate conditions are unsuitable for painting. DeFelsko states that the instrument is intended for surface preparation checks required by ISO 8502-4, BS 7079-B4, ASTM D3276, IMO PSPC, SSPC-PA 7 and US Navy NSI 009-32.

Technical specifications

The gage body measures 127 x 66 x 25.4 mm (5 x 2.6 x 1 in.) and has an IP65-rated enclosure, a 2.8 in. colour touchscreen and a rubber holster. It is supplied with humidity and temperature sensors, wrist strap, 3 AAA batteries, instructions, carrying case (hard shell case for the DPM S), lens shield, a long-form Certificate of Calibration traceable to NIST and a two-year warranty on body and probe.

Probe styles and ordering codes

The probe order guide lists five styles. The DPM is an integral probe, the DPM IR adds an infrared surface temperature sensor, the DPM S has a cabled surface temperature sensor, the DPM A adds a wind speed sensor and the DPM D is a cabled probe with 1/2 in. NPT threads that reads air temperature, relative humidity and dew point only. Order codes carry a version digit: DPM1, DPMIR1, DPMS1, DPMA1 and DPMD1 are Standard gages, and DPM3, DPMIR3, DPMS3, DPMA3 and DPMD3 are Advanced gages. Probe-only codes are PRBDPM, PRBDPMIR, PRBDPMS, PRBDPMA and PRBDPMD. Wet bulb temperature is shown on Advanced models only.

Logging and selection

Standard models store 2,500 datasets, and Auto Log mode records climate parameters at selected intervals, running unattended on batteries for up to 60 hours or continuously through USB. Advanced models store 250,000 datasets in up to 1,000 batches and include WiFi and Bluetooth. Field-replaceable, pre-calibrated relative humidity and air temperature sensors are available on the PRBDPM and PRBDPMIR probes. The DPM IR reads surface temperature without contact, the DPM S uses a cabled surface sensor, and the DPM D, with its 1/2 in. NPT threaded cabled probe, does not measure surface temperature. For the dew point comparison, the Elcometer 319 dewpoint meter is also listed; see all portable test and measurement instruments.

Documents and quotation

The attached DeFelsko datasheet gives the specifications and the probe ordering codes. Please confirm before ordering the probe style, Standard or Advanced version, whether wind speed or infrared surface temperature is needed and the standard you work to, and send the details with your enquiry so the code can be checked against the manufacturer documentation.