HMP378 probe for pressurized pipelines - HMT370EX

HMT370EX User Guide

Document code
English (United States)
Document type
User guide

The HMP378 probe option is especially suitable for measurements inside pipelines. Due to its sliding fit (available probe lengths: 226 mm and 448 mm (8.90 in/17.6 in)), HMP378 is easy to install into and remove from a pressurized process. A ball valve kit (Vaisala item code: BALLVALVE-1) is available for connecting the probe to a pressurized process or pipeline.

Installation options

For instructions on installing HMP378 into a process with the fitting body (R1/2”ISO7/1 or NPT1/2”) of the probe, see Attaching HMP378 to process with fitting body.

For instructions on installation with the optional ball valve kit, see Attaching ball valve kit to process and Installing HMP378 with ball valve kit BALLVALVE-1.


HMP378F and HMP378H probe variants for measuring oil and JET A-1 fuel moisture

The HMP378F and HMP378H probe options are variants of the standard HMP378, designed for measurements in oil (HMP378F; default calculation coefficients valid for transformer oil) and JET A-1 fuel (HMP378H). They provide a specialized selection of measurement parameters (see Table 2) intended specifically for oil and JET A-1 fuel measurements. With HMP378F, oil-specific calculation coefficients can be configured into use to customize the measurement for a specific oil type: see Configuring calculation coefficients.

For more information on HMP378F, see HMP378F probe option for measuring oil moisture and temperature.

For more information on HMP378H, see HMP378H probe option for measuring JET A-1 fuel moisture and temperature.


Figure 1. Dimensions in mm (inches)


Table 1. HMP378 for pressurized pipelines
Property Description/value
Temperature range -70 … +180 °C (-94 … +356 °F)
Pressure range 0 … 4 MPa
Probe cable length 2, 5 or 10 meters (6 ft 7 in, 16 ft 5 in, 32 ft 10 in)
Probe diameter 13.5 mm/12 mm (0.53 in/0.47 in)
Available probe lengths 226 mm/448 mm (8.90 in/17.6 in)
Fitting body ISO1/2 solid structure DRW212076SP
Fitting body NPT1/2 solid structure NPTFITBODASP
Ball valve ISO 1/2 with welding joint BALLVALVE-1