Morris Products 57085 User manual

PORTABLE DIGITAL
CAPACITANCE
METER
Model 57085
1. GENERAL
1.1 INTRODUCTION
This Digital Capacitance Meter gives a direct reading of capacitance on a 3 1/2 digits LCD display.
Nine ranges give precision readings from 0.1pF to 20mF, which includes virtually all capacitors
used in electronic engineering laboratories, production, service shops and schools. Its battery
operation, light weight, and small size make it a truly portable instrument.
1.2 FEATURES
* 21mm LCD display provided. MAX indication 1999.
* 9 Ranges from 200pF to 20mF.
* High accuracy in measuring.
* External knob adjustment of the zero value of the display, approx ±20pf.
* Dual - Slope integration A/D converter.
* Overload indication of “1”.
* Safety designed test probe.
* Size: 31.5mm ×91mm ×189mm (H ×W ×L).
* Weight: 240g (including battery).
2.. SPECIFICATIONS
Accuracy is specified for a period of one year after calibration and at 18°C to 28°C (64°F to 82°F)
with relative humidity to 80%.
2.1 GENERAL
POWER SUPPLY 9V battery NEDA 1604 or 6F22 006P
LOW BATTERY INDICATION “ ” appears on the display
FUSE PROTECTION 200mA/250V
EXCITATION VOLTAGE 2.8V peak, MAX
OPERATING TEMPERATURE 0°C to 40°C (32°F to 104°F)
STORAGE TEMPERATURE −10°C to 50°C (14°F to 122°F)
2.2 ELECTRICAL SPECIFICATIONS
Range Resolution Accuracy Test Frequency
200pF
0.1pF
±0.5%of full scale ±1 digit
800Hz
2nF
1pF
±
0.5
%
of full scale
±
1 digit
800Hz
20nF
10pF
±0.5%of full scale ±1 digit
800Hz
200nF
100pF
±0.5%of full scale ±1 digit
800Hz
2
µ
F
1000pF
±
0.5
%
of full scale
±
1 digit
800Hz
20µF
0.01µF
±0.5%of full scale ±1 digit
80Hz
200µF
0.1µF
±0.5%of full scale ±1 digit
8Hz
2000
µ
F
1
µ
F
±
1.0
%
of full scale
±
1 digit
8Hz
20mF 10µF ±2.0%of full scale ±2 digits 8Hz

3. FRONT PANEL
1. LCD DISPLAY
2. ROTARY SWITCH
3. ZERO ADJUSTOR
4. INPUT JACKS
4. OPERATING INSTRUCTION
4.1 CAUTION BEFORE MEASUREMENT
1. Be sure that batteries are correctly placed in the battery case and connected to the battery snap.
2. Observe polarity when connecting polarized capacitors.
3. Fully discharge any capacitors.
4. Never apply voltage to the test jacks, serious damage may result.
5. Do not short the test leads together. This will cause x-large power consumption of the battery.
It will show over-range indication on all ranges.
4.2 CONSIDERATION
1. If the capacitance value is unmarked, start with the 200pF range and keep increasing until the
over-range indication goes off and a reading is obtained.
2. A shorted capacitor will read over-range on all ranges. A capacitor with low voltage leakage will
read over-range, or a much higher value than normal. An open capacitor will read zero on all
ranges (possibly a few pF on the 200pF range).
3. Measurements of very low capacitances should be performed using extremely short leads or the
capacitor measuring socket above input jacks in order to avoid introducing any stray capacitance.
4. When using the optional test leads, remember that the leads introduce a measurable capacitance
to the measurement.
As a first approximation, the test lead capacitance may be measured by opening the leads at the
tips, recording the open circuit value and subtracting that value (if the value is negative than
adding) from the display results. However, in order for this correction to be valid, the succeeding
capacitor measurement must be made with all other measurement conditions exactly the same.
5. Capacitors, especially electrolytics, often have notoriously wide tolerances. Do not be surprised if
the measured value is greater than the value marked on the capacitor, unless it is a close
tolerance type. However, values are seldom drastically below the rated value.
6. The existence of a leaky capacitance may be detected if the value changes significantly as the
scales are changed. The effect of the internal leaky resistance is minimized on the lower range
scales.
4.3 CAPACITANCE MEASURING PROCEDURE
1. Select the range switch for the maximum expected capacitance.
2. Check the zero display: If your test range on 200pF, 2nF 20nF. Before connecting the capacitor
under test (but after inserting any test leads or test fixtures). Rotate the front - panel adjust knob
for a zero display. This “ZREO ADJUSTMENT” is limited to approx. 20pF to ±20pF.
3. Connect the alligator clips to capacitor leads or insert leads of the capacitor into its measuring
socket.
4. Read the display. The measuring value is a direct reading and the electrical unit (pF, nF, µF, mF)
is indicated. If DISPLAY show “1“. It indicates on Out-of-Range measurement. If the display
indicates one or more leading zero’s, shift to the next lower range scale to improve resolution of
the measurement.
5. ROTARY SWITCH: Be sure to set to “OFF” position when not using.

5. MAINTENANCE
* When the left corner of LCD display shows “BAT“. It is necessary to replace the battery. Remove
screws on the back cover and open the case. Replace the exhausted battery with a new one.
* Fuses rarely need replacement and blow almost always as a result of the operator’s error. Open
the case as mentioned above, and then take the PCB out from the front cover. Replace the blown
fuse with one containing the same ratings (200mA/250V quick acting).
* If any faults or abnormalities are observed, the meter cannot be used anymore and it has to be
checked out.
* Never use the meter unless the back cover is in place and fully fastened.
* Do not use abrasives or solvents on the meter; use a damp cloth and mild detergent only.
6. ACCESSORIES
6.1 SUPPLIED WITH THE CAPACITANCE METER
Test Leads
Battery 9V NEDA 1604 or 6F22 006p
Operating Manual
Holster
6.2 HOW TO USE THE HOLSTER
The holster is used to protect the meter and to make the measurement more comfortable, It comes
with two stands installed together. The figure shows how to use the holster to:
1. Support the meter with a standard angle.
2. Support the meter with a small angle using the little stand.
3. Hang the meter on the wall using the little stand. Take the little stand off from the back side of the
large stand and insert it into holes located upper on the holster.