GENERAL DESCRIPTION
The Model 740A is a general purpose rigid probe for
use with Robertshaw capacitance instruments. It is used for level
measuring applications involving liquids or dry materials. Available
either bare (non-insulated) or Teflon insulated for use in conductive
solutions. The Teflon electrode insulation has a Teflon wall thickness of
1/16" over a 7/32" 316 stainless steel sensing rod. The Teflon insulated
probe is recommended for use on low viscosity liquids and low to medium
density granular materials. (For abrasive or agitated products, see
Robertshaw Model 728B Heavy Duty probes.)
The Model 740A Probe has been designed to ensure
long, trouble-free life. Extra tight fitting Teflon insulation has been
incorporated into the design of the Model 740A Probe series. This
insulation is continuous through the total length of the probe including
the gland with an internal stainless steel sheath over the Teflon inside
the gland. If a seal should break down and allow leakage into the gland,
this internal construction is such that the measurement will not be
affected and reliable readings will continue.
The Model 740A Probe, except as noted, conforms
to the requirements of the National Association Of Corrosion Engineers (NACE)
specification MR0175-88 (Material requirements For Resistance To Sulfide
Stress Cracking For Oilfield Equipment).
The Model 740C Probe is a Model 740A Probe that
has been registered in Canada as a pressure containing fitting and bears
the Canadian Registration Number (CRN). All specifications for the Model
740C, except as noted, are identical to the specifications for the Model
740A Probe.
