Fluke Biomedical 07-487 - Manual (Page 6)

Nuclear Associates 07-487
Operators Manual
1-2
1.4 Specifications
Range No. 1: 199.9 mAs max, over-range indication at 160.0 mAs
Range No. 2: 1999 mAs max, over-range indication at 1600 mAs
Input Current: 25 to 1250 mA
Accuracy: ± 2% (± 1 digit)
Load: Full wave bridge feeding 5 ohm - 5W
Recalibration: Annually
Battery: 9 V Alkaline
Display: 3 ½ digits, + sign, LO BAT
Input Connectors: 24” test leads with insulated alligator clip
Dimensions (H x W x D): 1.1 in. x 3.5 in. x 5.7 in. (2.8 cm x 8.9 cm x 13.7 cm)
Weight: 0.46 lbs. (0.21 kg)
Operating Conditions:
+10° to 40° C (+50° to 104° F)
Maximum 90% relative humidity, non-condensing
CAUTION
Routine Cleaning: Do NOT immerse model 07-487
Dual Range Digital mAs Meter. The unit is not
waterproof. Liquid could damage the circuits. The
unit should be kept clean and free from dirt and
contamination. The unit may be cleaned by wiping
with a damp cloth using any commercially available
cleaning or decontaminating agent.
1.5 Connection and Use of the mAs Meter
The mAs meter is designed to be connected in the ground return line of the high voltage transformer and
must be in the actual current path of the x-ray tube. The meter can be connected in series with the
rectified tube current (DC path), via the DC input jacks or it can be connected using the AC input jacks in
series with the transformer down stream of the rectifier (AC path). However, all the tube current must go
through the mAs meter to have an accurate reading. If an alternate or parallel current pathway of the x-
ray generator is used, it could bypass the meter and invalidate the reading. Do not use resistors,
varistors, bypass or distributed capacitors in parallel with the meter. This may affect the calibration.
Before using the mAs meter, examine the circuit of the x-ray generator and be certain that the mAs meter
is connected so that such components will not affect the readings. Varistors which have limiting voltages
above 10 Volts will probably not disturb the reading.
1.6 Circuits That Do Not Permit the Use of the mAs Meter
Certain circuits will not permit the use of the mAs meter. Some dental tube heads do not provide access
to the tube current and are adjusted by observing the primary AC current. Some systems use electronic
control circuits with part of the control network inside the tube head and are adjusted by setting the
control amplifier to specific reference voltages. Some high frequency generators require that the ground
return