User`s manual
MTEK6000 SERIES USER'S MANUAL 
January 2002  2-9 
INSTALLING THE THERMAL PROBE 
A thermal (temperature) probe is connected 
to the MTEK6000 by a 6-foot (2-meter) 
cable. You should coil excess cable to 
prevent possible damage. The probe is 
designed to fit into standard Metretek, Inc. 
thermowells. Optional 15-foot (4.5 meter) 
and 30-foot (9-meter) cables are available.  
See Fig 2-10. 
To install the thermal probe, use the supplied 
temperature probe adapter. Refer to Table 
2-1. Insert the probe into the thermowell and 
tighten the securing nut FINGER TIGHT 
only. The standard adapter is a ½” fitting.  
Users retrofitting instruments requiring the 
5
/
8
” adapter can order the adapter from 
Metretek, Inc. 
Oil or ethylene glycol (antifreeze) should be 
used to improve heat transfer from the 
thermowell to the thermal probe. Be aware, 
however, that it is possible to cause hydraulic 
crushing of the probe. This can happen when 
there is little or no air in the thermowell 
above the probe. When the probe is fastened 
by tightening the securing nut, the space in 
the well decreases as the probe enters. As a 
result, hydraulic pressure may rise high 
enough to cause damage. If you use oil or 
antifreeze, make sure there is enough air 
in the thermowell above the fluid to 
prevent crushing the probe. 
It is recommended that the thermowell be 
installed in the meter outlet pipe one or two 
diameters from the meter outlet. The 
insertion length of the thermowell must be 
sufficient to extend at least to the pipe center, 
but no further than 75% of the pipe’s 
diameter. Thermowells should not be situated 
where they will be exposed to direct sunlight.  
A sunshield should be used for installations 
where this cannot be avoided. 
Table 2-1:  Thermowell  Part Numbers 
Pipe Size  Insertion 
Length 
Thermowell 
Part Number 
4 in. 
2 ½ in.  5340-0373  ½” NPT 
5340-0377  ¾” NPT 
5340-0384 1” NPT 
6 in. 
8 in. 
4 ½ in.  5340-0372  ½” NPT 
5340-0376  ¾” NPT 
5340-0383 1” NPT 
12 in. 
14 in. 
7 ½ in.  5340-0371  ½” NPT 
5340-0375  ¾” NPT 
5340-0379 1” NPT 
16 in. 
20 in. 
10 ½ in.  5340-0370  ½” NPT 
5340-0374  ¾” NPT 
5340-0378 1” NPT 
Figure 2- 8 Temperature Probe Connection 










