CD800a

DIGITAL MULTIMETER
INSTRUCTION MANUAL
【1】SAFETY PRECAUTIONS Before use, read the following safety precautions.
This instruction manual explains how to use your new digital multimeter
CD800a safely. Before use, please read this manual thoroughly. After reading
it, keep it together with the product for reference to it when necessary.
The instruction given under the heading of “ WARNING” must be
followed to prevent accidental burn or electrical shock.
1-1 Explanation of Warning Symbols
The meaning of the symbols used in this manual and attached to the
product is as follows.
Very important instruction for safe use.
The warning messages are intended to prevent accidents to
operating personnel such as burn and electrical shock.
The caution messages are intended to prevent damage to the
instrument.
：Ground ：Diode ：Fuse
：Buzzer ：Capacitance Ω：Resistance
：Direct current(DC) Hz：Frequency
％ ：Duty cycle ～：Alternating current(AC)
：Double insulation(Protection ClassⅡ)
＋ ：Plus input (Red) －：Minus input (Black)

1-2 Warning Instruction for Safe Use

WARNING
To ensure the meter is used safely, be sure to observe the instruction
when using the instrument.
1.Never use meter on the electric circuits that Exceed 3 kVA.
2.Never apply an input signal exceeding the maximum rating input value.
3.Never use meter if the meter or test leads are damaged or broken.
4.Pay special attention when measuring the voltage of AC 30 Vrms(42.4
V peak) or DC 60 V or more to avoid injury.
5.Never use meter for measuring the line connected with equipment
(i.e.motors) that generates induced or surge voltage since it may
exceed the maximum allowable voltage.
6.Never use uncased meter.
7.Be sure to use a fuse of the specified rating or type. Never use a
substitute of the fuse or never make a short circuit of the fuse.
8.When connecting and disconnecting the test leads, first connecting
the ground lead(black one). When disconnecting them, the ground
lead must be disconnected last.
9.Always keep your fingers behind the finger guards on the probe when
making measurements.

－ 1 －
 10.Be sure to disconnect the test pins from the circuit when changing
the function.
11.Before starting measurement, make sure that the function and
range are properly set in accordance with the measurement.
12.Never use meter with wet hands or in a damp environment.
13.Never open tester case except when replacing batteries or fuse.
Do not attempt any alteration of original specifications.
14.Do not use the device near an item of strong electromagnetic
generation or a charged item.
15.To ensure safety and maintain accuracy, calibrate and check the
tester at least once a year.
16.The multimeter is for indoor use only.

1-3 Overload protections

Function Input Maximum rating Maximum overload
terminals input value protection input

V DC・AC 600 V
＋
(Red) DC 600 V
Voltage and AC 600 V or Peak
Ω/ / / Current input Max 840 V
prohibited
－
Hz / % (Black) DC・AC 600 V
mA DC・AC 400 mA 0.5 A / 250 V Fuse
※AC voltage is regulated by rms, valus of sinusoidal wave.
CAUTION
1. Correct measurement may not be performed when using the meter
in the ferromagnetic / intense electric field such as places near a
transformer, a high-current circuit, and a radio.
2. The meter may malfunction or correct measurement may not be
performed when measuring special waveform such as that of the
inverter circuit.

【2】APPLICATION AND FEATURES

2-1 Applications
This instrument is portable digital multimeter designed for measurement
of weak current circuits. It plays an important role in circuitry analysis by
using additional functions as well as measurements of small type
communication equipment, electrical home appliance, lighting voltage and
batteries of various type.

－ 2 －
2-2 Features
●Sharp contrast LCD with character 17.5 mm high is employed, and unit
symbols are displayed on the screen of the LCD.
●Frequency, capacitance and duty cycle measurement function.
●Attachment body cover is used for protection of the meter and as a tilt
stand.
●The current function is protected by a fuse.

【3】NEME OF COMPONENT UNITS

Hand strap
Multimeter Display
Test Leads
CD800a 4000 Count

RANGE Test Pins

hold button

Finger Guards
SELECT RANGE △REL HOLD Hz %

SELECT button
AUTO POWER OFF

OFF
RELATIVE V ～
Ω
Test Probe
button （Red）
Hz %

DATA HOLD mA Test Probe

～
button MAX 400mA
FUSED
－＋
（Black）

Hz / % DIGITAL
～ 600V MAX(CAT. Ⅲ)

select button MULTIMETER

Removable
test pin covers
POWER switch and FUNCTION switch

Body Cover
When not covered

Stopper

－ 3 －
【4】DESCRIPTION OF FUNCTIONS
WARNING
In the case of action or cancel that function as follows, do not turn the
function switch in the condition applied input.

4-1 Function Switch

Turn this switch, to turn on and off the power and to select the
functions of V ～, Ω/ / / , Hz/%, mA ～
4-2 SELECT：Measurement Function Select
When the SELECT button is pressed (→), the functions change as follows.
・In the case of V, mA, the modes change as： → ～ →
・In the case of Ω, , , , the modes change：Ω→ → → →Ω
4-3 RANGE：Range Hold
Press the RANGE button momentary to set the manual range mode,
then ‘AUTO’ disappears in the display. In manual range mode, press the
button again to step through the ranges. To return to the auto mode,
press the button for 1 sec. or more, then ‘AUTO’ is shown.
※Manual mode is not available in , Hz, duty measurement, diode
check, cont. buzzer functions.
4-4 △REL：Relative Mode
Relative zero allows the user to offset the meter consecutive
measurements with the displaying reading as the reference value. Press
the △REL button momentarily to activate and to exit relative zero mode.
4-5 HOLD：Data Hold
When the HOLD button is pressed, the display is hold (‘DH’ is shown
on the display). The display will not be changed while the function is
active. Press the button again to cancel the function.(‘DH’ on the
display disappears.)
※DATA HOLD function does not work when measuring frequency.
4-6 Hz/%：Frequency and duty cycle select button
Frequency and duty cycle measurement functions are activated alternatively
by pressing the button. In the case of the mode change as Hz → %
4-7 Auto Power Off
The meter will enter a low power consumption sleep mode automatically
to extend battery life after approximately 30 minutes of no function switch
or push button operations. To wake up the meter from Auto Power Off,
press any buttons momentarily or turn the function switch to the OFF
position. Then turn back on again. To disable the Auto Power Off feature,
press the SELECT button while turning the function switch on.
※Always turn the function switch to the OFF position when the meter
is not in use.
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【5】MEASUREMENT PROCEDURE
5-1 Start-Up Inspection
WARNING
1. Make sure that no low battery indication appear in the display.
2. Never use meter if the meter or test leads are damaged or broken.
3. Check continuity of test leads & fuse.
※ No display may suggest that a battery be exhausted.

START

Check
Main unit Damaged ②
and test leads
damaged?

No damaged
①
Check continuty of test
leads.

①Set the function at " ".

②Short the red and

black test pins.

No Stop using it and have

The buzzer sounds?
it repaired.
Yes
No problem.
Start measurement.

5-2 Voltage measurement

WARNING
1. Never apply an input signal exceeding the maximum rating input value.
2. Be sure to disconnect the test pins from the circuit when changing the function.
3. Always keep your fingers behind the finger guards on the probe when
making measurements.

DCV / ACV : Maximum rating input value 600 V DC/AC

1) Applications
DCV : Voltage of the battery and DC circuit are measured.
ACV : Sine wave AC voltage, such as lighting voltage, is measured.
2) Measuring ranges
DCV : 5 ranges from 400 mV to 600 V
ACV : 4 ranges from 4 V to 600 V

－5 －
3) Measurement procedure
① Set the FUNCTION switch at “V” and select either DC or AC with the
SELECT button.
② Apply the red and black test pins to the circuit to measure.
● For measurement of DCV, apply the black test pin to the negative
potential side of the circuit to measure and the red test pin to the
positive potential side.
● For measurement of ACV, apply the red and black test pins to the
circuit to measure.
③ The reading of Voltage is shown on the display.
④ After measurement, release the red and black test pins from the
object measured.
◇ Readings are unstable when test leads are opened.
◇ Accuracy is guaranteed in the case of sine wave (Bandwidth 40 ~
400 Hz)
◇ 400 mV AC range is not specified.
◇ In the manual mode of the ACV function, the CD800a can be set to the
400 mV range and shows an approximate value. But its accuracy is not
guaranteed.
◇ In the AC 4 V range, a figure of about 3～9 counts will stay on even if
no input signal is present. But it is not malfunction.
◆ Use Hz/% function for making Hz and duty cycle measurements.
Battery
④ ④ DCV measurement
③
②
V

④ ④
①

ACV measurement

Outlet

5-3 Resistance Measurement (Ω)

WARNING
Never apply voltage to the input terminals.

1) Applications
Resistance of resistors and circuits are measured.
2) Measuring ranges
6 ranges from 400Ω to 40 MΩ.

－ 6 －
3) Measurement procedure
① Set the FUNTION switch at Ω/ / / and select Ω with the
SELECT button.
② Apply the red and black test pins to an object to measure.
③ The reading is shown in the display.
④ After measurement, release the red and black test pins from the object measured.
Note : If measurement is likely to be influenced by noise, shield the
object to measure with negative potential (COM). If a finger
touches a test pin during measurement, measurement will be
influenced by the resistance in the human body, and that results
in measurement error. Open Circuit Voltage: <0.4 VDC typical.
● When the presence of voltage, resistance measurement can not work.

②
③
④ ④
Ω

① Resistor

5-4 Testing Diode ( )

WARNING
Never apply voltage to the input terminals.
1) Applications
The quality of diodes is tested.
2) How to use
① Set the FUNTION switch at Ω/ / / .
② Select by pressing the SELECT button.
③ Apply the black test pins to the cathode of the diode and the red test pin to the anode.
④ Make sure that the display shows a diode forward voltage drop.
⑤ Replace the red and black test pins, make sure that the display is “OL” reading.
⑥ After measurement, release the red and black test pins from the object measured.
● The input terminals open voltage is about 1.5 V
Cathode ③ Anode
④
②

① ⑥ ⑥

⑤
Diode
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5-5 Checking Continuity ( )
WARNING
Never apply voltage to the input terminals.

1) Applications
Checking the continuity of wiring and selecting wires.
2) How to use
① Set the FUNTION switch at Ω/ / / .
② Select by pressing the SELECT button.
③ Apply the red and black test pins to a circuit or conductor to measure.
④ The continuity can be judged by whether the buzzer sounds or not.
⑤ After measurement, release the red and black test pins from the object measured.
● Threshold : 10~120 Ω

③
④
⑤ ⑤
②

① Extension cord

5-6 Capacitance Measurement ( )

WARNING
Never apply voltage to the input terminals.

CAUTION
1. Discharge the capacitance before measurement.
2. This is not suitable for measurement of electrolytic condenser such
as a large leakage condenser.
3. It takes a while to measure large capacitance.

1) Applications
Measures capacitance of low leakage condenser such as film
condenser.
2) Measuring ranges
5 ranges from 50.00 nF to 100.0μF (Auto range).

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3) Measurement procedure
① Set the FUNTION switch at Ω/ / / .
② Select by pressing the SELECT button.
③ Press the REL button for zero setting (00.00 nF).
④ Apply the red and black test pins to a conductor to measure.
⑤ Read the value on the display.
⑥ After measurement, release the red and black test pins from the object measured.
● Manual range is not available in capacitance measurement.
● Readings are unstable because of stray capacitance in test leads or noise.

Capacitor
⑤
⑥ ⑥
②
③
①
④

5-7 Hz / % Measurements ( Hz / % )
WARNING
Never apply an input signal exceeding the maximum rating input value.

1) Applications
Measures frequency and duty of any circuit.
2) Measuring ranges
6 ranges from 5 Hz to 100 kHz (Auto range)
Duty Cycle : 20 %~80 %
3) Measurement procedure
① Set the function switch at Hz / % function.
② Select Hz by pressing Hz/% selection button.
③ Apply the red and black test pins to a conductor to measure.
④ Read the value on the display.
⑤ After measurement, release the red and black test pins from the object measured.
● HOLD function does not work in Frequency measurement function.

④
⑤ ⑤
②
Hz ％

① ③

－ 9 －
5-8 Current Measurement
WARNING
1. Never apply voltage to the input terminals.
2. Be sure to make a series connection via load.
3. Do not apply an input exceeding the maximum rated current to the
input terminals.
4. Before starting measurement, turn OFF the power switch of the
circuit to separate the measuring part, and then connect the test
leads firmly.

Power source Power source

Load Load
（×） （○）

mA mA

● DCmA：Maximum rating input value 400 mADC

● ACmA：Maximum rating input value 400 mAAC
1) Applications
DCA：Current in batteries and DC circuits is measured.
ACA：Current in AC circuits is measured.
2) Measuring ranges
DC/ACmA：2 ranges for 400.0 mA and 40.00 mA.
3) Measurement procedure
① Set the function switch at “mA” and select either DC or AC with the SELECT button.
② In the circuit to measure and apply the red and black test pins in series with load.
● For measurement of DCA, apply the black test pin to the negative
potential side of the circuit to measure and the red test pin to the
positive potential side in series with load.
● For measurement of ACV, apply the red and black test pins to the
circuit to measure in series with load.
③ Read the value on the display.
④ After measurement, remove the red and black test pins from the circuit measured.
◆ Use Hz/% function for making Hz and duty cycle measurements.

③ Power
source Load

④ ④
① mA

－ 10 －
【6】MAINTENANCE
WARNING
1. The section is very important for safety. Read and understand the
following instruction fully and maintain your instrument properly.
2. The instrument must be calibrated and inspected at least once a
year to maintain the safety and accuracy.

6-1 Maintenance and inspection

1) Appearance
● Is the appearance not damaged by falling?
2) Test leads
● Is the cord of the test leads not damaged?
● Is the core wire not exposed at any place of the test leads?
Note：If the built-in fuse is blown, only the current measurement becomes impossible.
Note：Make sure that the test leads are not cut, referring to the section 5-1.
6-2 Calibration
The manufacturer may conduct the calibration and inspection. For
more information, please contact the dealers.
6-3 Battery and Fuse Replacement
WARNING
1. If the rear case or the battery lid is removed with input applied to
the input terminals, you may get electrical shock. Before starting
the work, always make sure that no input is applied.
2. Before starting the work, be sure to turn OFF the main unit power
and release the test leads from the circuit.
3. Be sure to use a fuse of the specified rating or type. Never use a
substitute of the fuse or never make a short circuit of the fuse.
① Remove the battery lid screw with a screwdriver.
② Take out the battery or fuse and replace it with a new one.
③ Attach the battery lid and fix with the screw.
CAUTION
Set battery with its polarities facing in the correct directions.
Rear case

Battery lid
R6(UM-3)
Fuse
0.5 A / 250 V
F1176
φ5×20 mm Battery lid screw
Blowout capacity
: 1.5 kA
－ 11 －
6-4 Storage
CAUTION
1. The panel and the case are not resistant to volatile solvent and must
not be cleaned with thinner or alcohol.
2. For cleaning, use dry, soft cloth and wipe it lightly.
3. The panel and the case are not resistant to heat. Do not place the
instrument near heat-generating devices (such as a soldering iron).
4. Do not store the instrument, in a place where it may be subjected
to vibration or from where it may fall.
5. For storing the instrument, avoid hot, cold or humid places or places
under direct sunlight or where condensation is anticipated.

【7】AFTER-SALE SERVICE
7-1 Warranty and Provision
Sanwa offers comprehensive warranty services to its end-users and to its
product resellers. Under Sanwa's general warranty policy, each instrument
is warranted to be free from defects in workmanship or material under
normal use for the period of one (1) year from the date of purchase.
This warranty policy is valid within the country of purchase only, and applied
only to the product purchased from Sanwa authorized agent or distributor.
Sanwa reserves the right to inspect all warranty claims to determine the
extent to which the warranty policy shall apply. This warranty shall not apply
to fuses, disposables batteries, or any product or parts, which have been
subject to one of the following causes:
1. A failure due to improper handling or use that deviates from the
instruction manual.
2. A failure due to inadequate repair or modification by people other than
Sanwa service personnel.
3. A failure due to causes not attributable to this product such as fire,
flood and other natural disaster.
4. Non-operation due to a discharged battery.
5. A failure or damage due to transportation, relocation or dropping after the
purchase.
7-2 Repair
Customers are asked to provide the following information when requesting services:
1. Customer name, address, and contact information
2. Description of problem
3. Description of product configuration
4. Model Number
5. Product Serial Number
6. Proof of Date-of-Purchase
7. Where you purchased the product
Please contact Sanwa authorized agent / distributor / service provider,
listed in our website, in your country with above information. An instrument
sent to Sanwa / agent / distributor without those information will be returned
to the customer.
Note:
1) Prior to requesting repair, please check the following:
Capacity of the built-in battery, polarity of installation and
discontinuity of the test leads.
－ 12 －
 2) Repair during the warranty period:
The failed meter will be repaired in accordance with the conditions stipulated in
7-1 Warranty and Provision.
3) Repair after the warranty period has expired:
In some cases, repair and transportation cost may become higher than the price of
the product. Please contact Sanwa authorized agent / service provider in advance.
The minimum retention period of service functional parts is 6 years after the
discontinuation of manufacture. This retention period is the repair warranty
period. Please note, however, if such functional parts become unavailable for
reasons of discontinuation of manufacture, etc., the retention period may
become shorter accordingly.
4) Precautions when sending the product to be repaired
To ensure the safety of the product during transportation, place the product in a box
that is larger than the product 5 times or more in volume and fill cushion materials
fully and then clearly mark “Repair Product Enclosed” on the box surface. The cost
of sending and returning the product shall be borne by the customer.
7-3 SANWA Website
http://www.sanwa-meter.co.jp
E-mail: [email protected]
【8】SPECIFICATIONS
8-1 General Specification
Measuring ΔΣmethod
Display 3 3/4 digit, 4000 counts
Sampling Rate Approx.3 times/sec
Auto and Manual ranges
Range Selection (Manual range or Auto renge only)
Over ranging lndication “OL” mark indication (except AC/DC 600 V ranges)
Automatic selection(“－” is indicated when negative
Polarity Indication voltage is inputted.)
Low Battery Indication Below approx. 2.4 V “ ” mark indication
Environmental Condition Operating altitude <2000 m / Pollution degreeⅡ
5 ℃～40 ℃ humidity range: Maximum 80 % RH for
Operating temperature temperatures up to 31 ℃ decreasing linearly to 50 % RH
at 40 ℃
Storage temperature / -10 ℃～50 ℃ 70 %R.H. max. No condensation. (remove
humidity range batteries)
Power Supply R06×2
AC sensoring Average sensoring
Battery Life 30 min. (auto power save)
Dimension L 176 mm×W 104 mm×H 46 mm
Mass Approx. 340 g
Power consumption Approx. 7 mW TYP. (at DCV)
Battery life Approx. 500 hours at DCV
Fuse 0.5 A / 250 V Fast Acting Fuse, Parts number:F1176
Accessories Instruction manual

－ 13 －
8-2 測定範囲及び確度 / Measurement Range and Accuracy
確度保証範囲：温度23±5 ℃ 湿度：80 %R.H.以下 結露のないこと
Accuracy assurance range : 23±5 ℃&less than 80 % R.H. No Condensation

rdg(reading)：読取値、dgt(digit)：最終桁のカウント数
ファンクション&レンジ 確 度 入力抵抗 備 考
Function&Range Accuracy Input Impedance Remarks

400.0 mV ±(0.7 %rdg＋3dgt) ≧100 MΩ

直流 電圧 4.000 V Approx. 11 MΩ
DCV 40.00 V
±(1.1 %rdg＋3dgt) 約10 MΩ
DC Voltage 400.0 V
Approx. 10 MΩ
600 V
4.000 V ±(1.6 %rdg＋9dgt) Approx. 11 MΩ
交流電圧 ※正弦波交流おける確度
40.00 V 確度保証周波数範囲40～400 Hz
ACV 約10 MΩ
400.0 V ±(1.6 %rdg＋5dgt) ※Accuracy in the cace of sin wave
AC Voltage Approx. 10 MΩ 40～400 Hz
600 V
400.0 Ω ±(1.5 %rdg＋5dgt)
4.000 kΩ 開放電圧：DC約 0.4 V
抵抗 40.00 kΩ ±(1.2 %rdg＋5dgt) Open voltage : Approx.DC 0.4 V
Ω 400.0 kΩ
測定電流は被測定抵抗の抵抗によって変化します。
Resistance 4.000 MΩ ±(2.0 %rdg＋3dgt) The measurering current changes according to the
resistance of the resistor to measure.
40.00 MΩ ±(4.0 %rdg＋3dgt)

50.00 nF ※オートレンジのみ。
静電容量 500.0 nF ※Auto range only.
表示されている値をリラティブ機能によって
5.000 μF ±(5.0 %rdg＋10dgt)
キャンセルした後の確度。
Capacitance 50.00 μF Accuracy was measured after canceling didplay
100.0 μF. value by relative key

－ 14 －
 5.000 Hz
50.00 Hz
周波数 ※オートレンジのみ。
500.0 Hz ※Auto range only.
Hz ±(0.5 %rdg＋3dgt)
5.000 kHz 1 Hz～1 kHz 4 Vrms～250 Vrms
Frequency 1 kHz～100 kHz 4 Vrms～20 Vrms
50.00 kHz
100.0 kHz

デューティー比 ※オートレンジのみ。
※Auto range only.
% 20～80 % ±(0.5 %rdg＋5dgt)
5 Hz～60 Hz 3 Vrms～30 Vrms
Duty Cycle 60 Hz～200 Hz 4.9 Vrms～30 Vrms

直流電流 約1 Ω
40.00 mA Approx. 1 Ω
DCmA ±(2.2 %rdg＋5dgt) ヒューズ抵抗を除く
400.0 mA Without resistance
DC Current of Fase
約1 Ω ※正弦波交流おける確度
交流電流 40.00 mA
Approx. 1 Ω
確度保証周波数範囲 40～400 Hz
ACmA ±(2.8 %rdg＋5dgt) ヒューズ抵抗を除く
※Accuracy in the cace of sin
Without resistance
AC Current 400.0 mA wave 40～400 Hz
of Fase

Checking Continuity 10～120 Ω以下で発音・開放電圧：DC約0.4 V

Buzzer sounds at less than 10～120 Ω・Open voltage:Approx.DC 0.4 V

Testing Diode 開放電圧：DC約1.5 V

Open voltage: Approx. DC 1.5 V

※トランスや大電流路など強磁界の発生している近く、また無線機など強電界の
発生している近くでは正常な測定ができない場合があります。
確度計算方法 / Accuracy calculation
例）直流電圧測定(DCmV) / For example…Measurement 400 mVDC Range.
表示値 / Display value : 100.0[mV]
レンジ確度 / Accuracy : 400.0[mV] レンジ / Range…±(0.3 %rdg+4dgt)
誤差 / Error : ±(100.0[mV]×0.3 %rdg+4dgt)=±0.7[mV]
計算式 / Calculation : 100.0[mV]±(100.0[mV]×0.3 %rdg+4dgt)
真値 / True value : ln a range of 099.3[mV]～100.7[mV]の範囲内。
※400.0[mV]レンジにおける4[dgt]とは、0.4[mV]に相当します。
※4[dgt] in the 400.0[mV]range correspond to 0.4[mV]

ここに掲載した製品の仕様や外観は改良等の理由により、予告なしに変更す
ることが有りますのでご承知ください。
Specifications and external appearance of the product described above may
be revised for modification without prior notice.

－ 15 －