Máy đo độ dẫn điện Emcee 1152
Model 1152 Digital Conductivity Meter
(ASTMStandard Test Method D 2624 included in
Specifications D975, D1655, and D7566)
Continuous standard electrical conductivity range
from 1 to 2000 in increments of 1 picosiemen per meter (pS/m)
Available in other standard and non-standard conductivity
ranges up to 20M pS/m
Large digital, liquid crystal display
Reliable advanced integrated circuit design technology
Self check calibration with field adjustment capability
Automatic over range and low battery indication
Capable of storage tank and tanker truck measurement with
the use of a short cable or cable reel kit
Powered by 3 readily available alkaline batteries
Electronics housed in a rugged cast aluminum case coated
with solvent resistant paint equipped with a detachable stainless steel probe
Approved intrinsically safe design for use in hazardous
environments by Underwriters Laboratories (UL) U.S, (UL) Canada and LCIE
(Europe)
Applications
The Model 1152 Digital Conductivity meter provides a
measurement of electrical conductivity of fluids in conductivity units (CU),
which are defined as picosiemens per meter in ASTM D2624. The rugged
Electro/mechanical design of the Model 1152 meter facilitates ease of use for
both laboratory and field applications. Initially the meter was designed and
developed for safety reasons to measure the electrical conductivity of
hydrocarbon fuels, particularly jet fuels. Subsequently, the meter was modified
with other conductivity ranges to accommodate measurement of a variety of
fluids for use in many different applications.
Safety
Hydrocarbon fuels typically have low electrical
conductivity and consequently are susceptible to retaining a static charge.
Static charges are induced, especially, when the fuel is pumped at high
rates through filters. Due to the relatively low conductivity, the static
charge does not readily dissipate and is retained for a considerable period of
time. This condition can result in an explosion and/or fire. Since
conductivity can vary with temperature it is important to record the
fuel temperature at which the measurement was performed.
Process Controls
In addition to safety reasons, electrical conductivity of
fluids can be monitored for process control. Proper addition and mixing of
various ingredients can be monitored at different stages of production. These
applications are not limited to hydrocarbons, but have been expanded to other
products; such as paints, solvents, inks, and other non-organic items. The
stainless steel probe is relatively unaffected by most acidic and caustic
solutions.
Theory of Operation
The EMCEE Model 1152 meter consists of an electronics
assembly and a detachable stainless steel probe. The probe, which is similar to
a capacitor having concentric electrodes, is immersed into the fluid up to the
set of holes closet to the electronics assembly. Depressing the “M” pushbutton
causes a relatively small direct current to flow through the fluid between the
electrodes. The current is amplified in the electronics assembly and is
displayed on the liquid crystal display in picosiemens per meter (pS/m).