HERMetic Onecal Thermometer for Marine Applications

Designed for use in hazardous environments (Zone 0), the Honeywell HERMetic Onecal is a highly accurate, intrinsically safe portable digital field thermometer for temperature verification inside tanks storing liquids.

Honeywell Tanksystem’s Onecal has been designed with users’ needs in mind. The cable, sensor and electronic display unit components can be changed without special tools or soldering. Recalibration is achieved by a simple ice point check that is easy to carry out without sending the unit to a laboratory, and without the need for a reference thermometer. Only the annual calibration verification, required by national standards, has to be performed against certified traceable reference thermometers. This translates into significant savings in transportation and repair costs, and a high degree of operational readiness.

Accurate temperature measurement is very important for volume calculation. This has been recognized by the international ISO 4268 standard (2000) and the American Petroleum Institute (API) Manual of Petroleum Measurement Standards (MPMS) Chapter 7 (2001). Honeywell’s Onecal helps users measure temperature accurately for spot-on volume calculation.

The ergonomic and rugged design of the housing allows for easy and safe cable storage. The cable guides keep the cable secured at all times. By counting the number of cable loops, the fed cable length can be determined.

1 Cable Loop = 2 feet

3 Cable Loops = 2 meters 

A 1° C / 2° F error in temperature measurement in case of crude oil and petroleum products can equate to an error of approximately 0.1 percent in the standard volume calculation. Great care is, therefore, required in the selection and calibration of temperature measurement equipment, and in the procedures used to determine representative average temperature data for bulk petroleum quantities. With Onecal, users benefit from reliable and accurate temperature measurement.