SPECIFICATIONS
SPECIFICATIONS
Input Limit: * range not to exceed 1999 mA.3
MODEL 168-20
Maximum current:
Tracking sate:
2
(mAs ran%a) 3000 ma nor. to axcaed .66 saeanh duratio
Gr~aCer than 3000 ma per miciosecand for rated accuracy
0375
.
MODEL 168-20
,
!( .
GENERAL INFORMATION
SECTION 1.
GENERAL INFORMATION
0375 3
‘INITIAL PREPARATION
SECTION 2.
INITIAL PREPARATION
Same as 168, however check zero end adjust if necessery.
The 168-20 m.Ae mere= should be used for making tie meeeuremen~e on
--
--__
x-ray machines only by people who ere fully familiar~with the mechiae
involved and the hazards rssocieted vich tie meenuremente. *n error
in meas”I‘ement technique could result in lethal shock hezards.
--
_ .,. .---~.-
.-..
-I_
MODEL 168-20
OPERATING INSTRUCTIONS
7-
SECTION 3.
.Ae a mm:
Ae e mA8 Meter: Refer to Model 168 manual for power selecrion details.
Connection LO X-Ray Machines:
designed for use with x-ray machines in the O-1999 WAS range. me m~8
meter muse be connected in series with the x-ray machine’s high voltage
secondary, between the secondary winding and ground. as ehovn In Figure
1. -Hose x-my machines have labeled ma or mAs fese poinrs for this
purpaee.
Place mAs-NOSN switch to NORM Qosftion. than refer to Wade1
168 manual for OMM operation.
Place nuts-NORM switch to m&s. For the o-1999 mAe range.
depress (DC) and (A).
the unit to 0 mAs and use the erase button whenever a
resee is desired.
OPERATING INSTRUCTIONS
Depress the erase button to redec
l”ne 168-20 rr& meter is specifically
r-----y --1
___-___
..- .~
---
0375
PIGlmE 1.
-~
Connection to X-Ray High Voltage Secondary,
5
-.__
-
OP!DATINC INSTRUCTIONS HODEL 168-20
WARNING
Consult r-ray machine service manual for proper hook up. since
improper connections can result in lethal voltages present on the
168-20 and damage to the meter.
side of the secondary. This will result in destruction of the
meter and a dangerous shock hazard. Never touch any part of the
wment circuit with Lhe high voltage on.
& over voltage protection device should be securely fasrened across rbe
ma or ntAs test points exrernally or internally LO protect both machines
and,che qperator in the event of an open circuit LO the m~8 meter (i.e..
teat lead falling off, blown fuge. etc.). Suitable procecrion devicea
include power resistors, epark gaps, etc.
protection devices should be obtained from the manufacturer of the x-ray
machine in quearion.
Figure 2 s@~s an alternate measurement technique for meesuring r&s. A
shunt resistor is securely installed across rhe ma or tie test points and
the 168-20 is used in the inre$raring voltege mode. Integrating voltage
mode is selected by pldcing the m&-NORM witch in the mAe position and
depressing (DC).
The shunt resistor should be wire wound, with a parer raring adequate for
the machine’s l~aximum current.
NEVER connect 168-20 co “high”
Specific information concernidg
m
0 * 199.9 *
0 + 1999 rk4.a
0 * 19990 *
This technique provides greater safety. multiple ranges. and greater input overload prorectioo or& the 168-20.
6
Shunt Reeiecor
10 n
1n
.1 n
0325
MODEL 168-20
L-
Other Uses:
OPERATING lNSTR"CTIO:iS
The 168-20 has 3 usable integrating ranges. ae fallows:
Function Setting (mAs/NOSN in mAa)
*
*
"e
Tie law mAs range bes 1000 ohm series re8is~ance, and should not be
used far x-ray tia measurements.
transformed into an mAa range by use of a sbunr resistor.
(DC) (A)
NOTE
The volt-second range can be
FCa*g*
0 - 1999 a.9
0 - 1.999 *
0 - 1.999 ve
----
r----
IO-MEG.
I I I I
TUBE
----.-. ~..--..
I
0375:
F1aw.E 2.
Int~graring Voltage Mae
7
MAqmNANCE
SECTION 4. MAINTENANCE
For All OEM Punctions: Refer CO Model 168 manual.
MODEL 168-20
PAR Xetcr Leakage Tese:
menc if nece8sary as outlined in Model 168 manual. Place meter in mAs
mode rich input open. reset vith erase buecon. Release button and time
drift WiLh a SLOp YBLCh.
seconds.
Pas Meter Accuracy Test:
or other current source adjusted for a 10.11 ma output. ~.eset the m~s
meter and. With a stop uacch. measure the time interval for the mAe
rehding co infrease from 100 mAa LO 1100 U.S. ‘nmelapsed time should be
100 sec. fl eec.
If drift is greater than this, repeat zero ad,usLnent.
Perform
Drift should t,e less than 1 dig,t per ten
Connecr mAs meter in mAs mode to a Keirhley 227
DC voltage zero check and zero adjust-
8
0375
Loading...