![background image](http://html1.mh-extra.com/html/ecc-x-ray/815/815_instruction-manual_3832519014.webp)
For dental x-rays with an output from 7 to 15 mA, place the instrument ½ to 2 inches
(2 to 5 cm) under the cone.
For kV of 40 to 50 kV, 15 to 50 mA a height of about 6 inches (15 cm) will work well.
Additional height will allow measurements at high kV and mA.
Measurements with plastic wrap
Many dental offices use a thin, transparent plastic cover over the x-ray head to help
with infection control. The plastic can induce measurement errors because of the
static charge that gets built up on the plastic. For best results remove the plastic
cover.
Pre-Heat
Many x-rays, particularly dental units with a single winding head excite the x-ray at a
lower voltage before the actual exposure in order to allow the filament to warm up.
Some of these x-rays emit radiation during this
“pre
-
heat”
time. This presents a
measurement problem. If the kVp reading appears to be inaccurate, check the
exposure time. If the measured exposure time is longer than the expected time, the
meter is picking up the pre-heat radiation. Increase the distance from the x-ray head
to the instrument. If the pre-heat radiation is significant, you may need to
experiment to find the right height.
14
Electronic Control Concepts
PO Box 182, 1160 US Route 50
Milford, Ohio 45150-9705 USA
Phone: 800-VIP-XRAY
Fax: 845-247-9028
[email protected] | www.eccxray.com
A Division of US Nuclear Corp
www.usnuclearcorp.com