A pH meter and probe with a screw-down connector that converts a standard BNC pH probe connector into an IP67 waterproof connection is disclosed.
Electrochemical pH meters are used to measure water quality and chemical solutions. Often, these meters make contact with the water or solution itself. Waterproof electrochemical meters have been available for some time. pH meters commonly use the pH industry standard BNC connector. The BNC connector is compatible with a wide selection of application specific pH probes, but is unfortunately not waterproof. When liquid is in contact with the connector, corrosion and other related problems can arise.
A number of solutions have been attempted to waterproof the probe connection none of them satisfactory. For example, BNC connectors on the meter are covered with a waterproof plug when not in use. When in use, however, the BNC connection is not waterproof. pH meters use non-standard, waterproof connectors specific to the manufacturer. These meters do not take advantage of the wide variety of pH probes compatible with industry standard BNC connectors. U.S. Pat. No. 4,702,710 purportedly discloses a BNC connector with a waterproof hood. However, movement in the probe cord, which happens when taking readings with the disclosed connector, opens a gap between the connector cover and the instrument allowing liquid to enter.
A need therefore exists for a waterproof BNC connector that overcomes those issues described above. These, as well as other related advantages, will be described in the present disclosure.
pH meter 100 is shown in
In operation, the user slides covering 410 down cable 108 to plug 404. When rotated, the internal threading of covering 410 locks into place with the external threading of body 304 of meter 100. O-ring 306 forms a watertight seal between body 304 and covering 410. As covering 410 is being rotated into the threading of body 304, another watertight seal is formed between covering 410 and probe cable 108 at junction 414.
The temperature probe connector is enclosed through covering 510. When screwed down covering 510 is also sealed at junction 514. Junction 514 is on cable 108 leading into plug 504. In operation, the user slides covering 510 down cable 108 to plug 504. When rotated, the internal threading of covering 510 locks into place with the external threading of body 304 of meter 100. O-ring 306 forms a watertight seal between body 304 and covering 510. As covering 510 is being rotated into the threading of body 304, another watertight seal is formed between covering 510 and probe cable 108 at junction 514.