KYORITSU New SNAP 7 User manual

I(IPERATING INSTRUCTI(IN I
ROTARY SCALE SNAP-ON
DC VOLT-OHM-AMMETER
IITIU SNRP 7
Our continuing research has made it possible for the instrument to be more free trom the
residual magnetism which is rncidental to this type of instrument designed to measure drrect
current only. our Kew snap-7 embodies the finest of our engineering experience and
knowledge in its compact form" An ideal instrument that can meet varying needs in the
automobile industry such as servicing at gas stations or repair shops, checking batteries and
regulators, and also diagnosing erectricar systems. Also, very useful for servicing and
ma;ntenance of various types of electrolystic equipment in the electro-chemicat lndustry.
For its funct;onal design and unique engineering concept our Kew snap-7 wiil prove to
be a fascinating service instrument to tlrose who work with variclus facilities related to the
telsphqps switchboards, electronic computors, electrolystic refinery and high voltage
electrostatic power appl icat ion.
O Provided with a warning lanrp that will autornatically inclicate the naed for battery
replacement when the instrument is in use.
O Powered by only one Eveready 216 (006p) rype gV battery which is readity availaole.
o integrated circuit boar<i used ensures the steady performarrce of the instrum€nt.
O Other features include the pointer lock system. voltage tesrleads ar.rd ohmprobe with
threadsd plugs. ohmprobe is also supplied with a fuse to protect the meter lrom
burnout. Like other Kew snap series our Kew snap-7 is packed with a number of such
outstanding features.

I SPECIFICATIONS
l. Measuring Range s
DC Current 0-10/75/ I 50/300/600A (5 Rangcs)
DC Voltage 0-3.0/30i 300V (3 Ranges)
Resistancc 0-2 K Q (25Q at nrid--scalc) (l Rangc)
2. Accuracy
Arnmeter, Voltmeter 13% of full scalc value (!4% at 600,4' rangc)
Ohmmeter +l'le of scale length
3. Dielectric Strength
2,200V AC (l minutc) between electrical oircuitry aud outside casc.
4. Meter Movement
Approx. 230 uA, 670 Q
5. Batteries
One 9 volt Eveready 216 battery (006P) and one l.5V
Eveready 815 (UM-3) battery.
6. Fuse
One 0.5A, l-20 (approx.) fuse.
7. Dimension
Approx" 255mrn(10.040") x 87mm(3.425 ') x 40mtn(I.575"i
8. Weight
Approx. 650g i23 oz)
9. Accessories
One se1 oi voltagr test leads, cne piece oi ohrnprobc, onc piece cf carrying case.
and one copy of operating instruction.
t2l

NOTE: I() F,NSI.,.RIJ T}IE N{AXI]\{LiN'I tsA.I.].F:RY 1,IFI], BE SURE TO SWITC}{ OI..F
l'lilr l-O\\'I'lR I'.XCI:-P'| WIILN MIIASLIRING CLRRtNT.
\IOLl',\(llr :'IrS'I I.FAilS AND OL{NtPR()Ittr: \1US'f IIE LIll-'T RFIN{OVEI)
i'l{.OU iiii lNSl RLirl!i:.N'i \\}ll:.}i NO'l RI'l()tilRtD IiOR !{EASLiRFINIt'INTS
I PRELIMINARY INSTRUCTION
After unpacking the KEWSNAP-7 you will find one 9v llveready 216(006P) battery and
one l.-5V L,veready 815(UM-3) battery (for ohmprobe) inside the box with the instrument.
Ilelore proceeding with measurements, install the Eveready 216 battery into the battery
contpartment(Fig.2) of thc instrument by rernoving two screws on the battery compartment
covcr (Fie. l).
Fig.- 1 Fig.-2
As for the.[veready 815 battery, refer to Fig. 21, page 9.
T CHECKING BATTERY
\\ll!-\ ('1lF-CKIN(; BAf lL,RY. I,lAKt'l SURt: ll{Af -flita I i-jN{'l I(lN 3l-.ill(l'f()R
-c'"VIl( ll lS FLA{.'ID 1N "flih "UA'f'I'.OI;F"' POSIl'lON.
Aftrrr the battery installation insert the prod of the voltage. test lcad into the
"BATT.CHECK" aperture located on the bottom of the instrument (Fig. 3). lf the mctcr
pointer cleflects and stays within the "BATT.OK" area of thc scale, the battcry is o.K.
Rcplace the battery if the pointer does not deflect up to thc "BATT.OK" area (Fig. 4).
F is.-3
(3)
Fin -A

I
t.
MEASURING DC CURRENT
(All current scales are printed in black)
Turn zero adjust screw to position the meter
pointer over the zero on the scale (Fig. 5).
2. PLACT] TIIE IJUNCTION S}.]LF]('TOR SWITC}I
IN THE "+'' POSITJON (POWI..R IS ON).
TURN THE RANGF] SELECTOR SWII'CII
KNOB UNTIL 600A SCALE APPEARS. TTIEN
'TURN "A CAL'' SWITCII KNOB ON THE
RIct{T SIDE O}r TtlE INSTRUMT'lN't (F'ig. 6)
TO ZT.,RO TI{I.i MT.]TI]R RTAI)IN(;.
TURN THE RANGT1 SI;LI]CTOR SWITCTI
KNOB trNTlL 300v (3.0v, 30v oR 30A)
SCALE. APPF.ARS. lF TIIII MLTITR POINIER
IS OI:I: TTIE ZERO POSITION SET ft TO
ZI'RO BY TURNING TIII.] "BALANCE''
KNOts LOCATI.]D ON T}IE TJPPI:R SEC'TION
Ol.' THE ITRONT CASE (Fig. 7).
A,(;AIN SI.]T fI{F- SCALT,] TO THI., 600A
RANGI, ANI) MAKH TTIL ZIIRO ADJIJS]'
lv{ENI WIftl 1.}llr "A ('AL" Swll'(l}l KNOll"
I{EPI]AI"T}IF] AI]OV h] PROCEDU RI:S TWICII
OR l'llRF.tl TIN'lf:lS S0 1'ltA'l'Tt{ERll IUAY
NOT OCCUR TFII] SIIIF"T O}.'I-TIE PoIN-TIR
Zt.]RO POSIl'ION.
-
o
t
tu
N
Fig.-5
F is.-6
F i9.-7
(4)

4. Set the dial drum scale to a desired ampere range and make sure that the meter is
zeroed. Press the jaw trigger to open the transfornrer jaws. When the conductor
tr: be measured is enclosed within the jaws, the ampere reading may be taken.
If the pointer is deflected in the opposite direction place the function selector srvitch
in the "-" position. When the current to be measured is of an unknown order
select the highest 600A range first and then the most appropriate range.
Fig. 8 shows the current flowing in the 'positive (*) direction and Fig. 9 in the
negative (-) direction.
NEGATIVE DIRECTION
READING
5. When a DC current is measured, a hysteresis effect may be introduced into the
transformer core. To remove this completely it is necessary to enclose a large AC
current carrying conductor within the jaws. It is also possible to minimize the
hysteresis effect by operating the jaw trigger a few trmes to open and close thc
transformer jaws. On the 30A range this hysteresis effect is the largest with 4 to
57o error in the meter indication. A highest degree of accuracy can be obtained when
the current being measured is a perfect DC currcnt.
5. Pointer lock is used to facilitate thc mcasute-
ment of conductors in areas of poor accessi-
bility or inadequate illumination. In such
cases, when the reading is registering on the
scale. simply slide the pointer lock button to
the left, to lock the pointer in place, and the
instrument'may be removed to an area where
it may be read easily, before releasing the
pointer (Fig. l0).
I
Fig.-8
I
-Er9m.-
v'f-
F is.-9
F ig.- l0
(5)

As described on page 3, make sure that the voltage test leads and ohmprobe arc
removed from the instrument during the current measurements. If the ohmprobe
is lell plugged in, the accuracy of the current measurement may be affected anrl
in addition the fuse located in the ohmprobe may be burned out so that the
reslstance measurement may not be made,
SNAP AROL)ND ONll CONDUCTOR ONI.Y (I:ig. ll). TII[, I\tE'ftjR WILL NOT
DIT,FLE('T IF TWO CONDUCTORS ARE I.NCLOSID WtTI{tN'I}iE.!AWS (Fig. 12).
DURING CURRENT MEASUREMENTS "REPLACE BAT]'L]RY'' LAMP ON THI:
SCALE PLA'tl1 LIGHTS tlP INDICATING THAT THE BATTIiRY IS WEAK.
Battery replacement may be made easily by removing the two screws on the battcry
compartment cover (Fig. 1) as illustrated on page 3.
Immediately after completing current measurements, place the lunction selector
switch in the "BATT.OFF" position. THE FUNCTION SELECTOR SWITCH
SHOUI-D ALSO BE LEI.'T ON THIS POSITION WHEN THE INSTRUMENT IS
NOT lN USI:.
F ig.- 12
(6)

I MEASURING DC VOLTAGE
(All voltagc scales are printed in red)
l. BEIiORI: VOLfA(;i: 1\'lllAStJRIrMEN'IS CHLIC'K 1'O Bl. SURI- IHAT TIILI POINTIIR
lS Rl,(;lsl taRING IIXA('T'LY ZERO. ADJtts tN'tFlNT, Wt{tN NFICDSSARY' MAY BI''
\'1,\l)t' BY NIEANS OIII lllr ZFIRO ADJUST SCRI-IW, I-OCIATED ADJACITN'I l'O TIll:
POINTIiR L,OCK (Fig. 5).
.t
J.
TIAKL, CLRTAIN TIIAT T[IF] FUNCTION STiLUC]TOR
PfJSI'TION. TIII.] N'IIi'I'IJR WII.,t- NOT DEFLECT WTIEN
P(Jsll'loN.
Thread the red voltage test lead into the "+V"
receptacle located on the bottom of the
instrument and black test lead into the "V. Q "
receptacle clockwise until they lock in securely.
(Fie.13).
Connect the rcd test lead (connecting end may
be either prod or clip) to the positive (+) side
of thc circuit under test and the black tcst lead
(connecting end either prod or clip) to the
negative (-) side. For example, connect the
clip of the test lead to one side of the circuit
under test and, holding the instrument in hand,
touch the prod of other test lead to other sidc
as shown in Fig. 14. If the pointer indicatcs
in excess of the ratcd 300V remove the tcst
lead from the circuit immediately.
6. The voltage test leads are constructed as shown in Fig. 15.
The prod can be removed by squeezing the rubber insulator.
swt]'crt ls IN ]'IIti "V. !l '
THH SWITCII IS I'N OI'III]R
F is.- 13
F ig.- 14
PROD
4. Turn the range selector switch knob until the 300V range appears in the window.
Note that the three volt ranges are provided in order of 3.0V, 30V and 300V full
scale. If the voltage under test is of an unknown order procecd with the voltagc
measurement from the highest 300V range.
THREADEO PLUG
,l
=<-_')--_1
-\---\
INSULA
F is,
F<Dq_
TOR
,-15
(71
CUP

I MEASURING RESISTANCE
(Ohm scale is printed in black)
INSFRT {Jill\{PR{irJl. l}i'iai lN51'R.1,1!,!1,.N'l: {}Nl. y 1il.lf li \It.ASURINC ItLStSi:1.NC!
l. liltrORl:. l\{AKING I{ilsISTAl\CL il{}lASURF.lvll-.Nl.S, BI: Sl,rRL. l HA'I 'f Ht ClRCL,l I
I,Nill--R TIIST IS "DFIAD""'THAT tS.'iiltrRE IS N0 vOl.'f;\GI C(;NNLtCfL-D.
IN CASL, OF ACCIDLNTAL CONTA(l'I OIj 'l-FiL DtilvtPR{J}l[. T{) \ "LIVE"
CIRCUIT ACCtiRATt', MI'IASUREMENTS CANNOI IJE \iADI1. ALTTIOt'(li{ lllt
FtrSE CON'IAINED lir- TIIE, OI{I\{PROBI'. WILL PROTITCT TIIE INSTRU\1[.N1'
F8.OM BURNOtIT.
2. Insert one of the voltage test leads into the "V. Q " receptacle located on the bottom
of the instrument, push firmly in and turn clockwise to lock (Fig. 16). Insert the
ohmprobe into the " Q " receptacle on the right side of the instrument, push ilrmly
in and turn clockwisc to lock (Fig. 17).
F ig.- 16
Maks sure that the pointer is on the " € "
mark of thc scale. lf not, set the pointer to
the " @ ", using the zcro adjust screw (Fig. 5).
When making this adjustment, do not short
the test leads (l.ig. 1 8).
F is.- 17
-
o
cc
ul
N
F is.- 18
(8)

5.
('lll:CK 'IO BI: SURhI 1'lIAl lllE F'UNCTITiN
SELEC'TOR SWIIC}I IS IN TIIE "V. Q ''
POSI'IION. Short the test lead prods and set
the pointer on the zero, using the " O .ADJ"
knob located on thc bottom of the instrument
(Fie. l9).
t
To measrue resistance clip one of the test leads
to one side of the circuit under tset and touch
the prod of the ohmprobe to the other side,
as illustrated in Fig. 20.
F ig.-20
The ohm :cale is located on the left side of the rolary scaie and i:: visible regardless
of the position of the rotary switch knob.
When replacing the battery and fuse, hcild the tear part ol t.he ohmprobe anC rotrl.r:
the froni part counter-clockwise to separate (Fig.2l). lihe battery and iuse then
can br removed for rcplacement. Use the 1.5V Eveready 815 battery and ilie t-ur:'
rated 0.5A. l-2 approx" (Do not use a fuse rated more than 0.5A).
F is.- 19
BATTERY
F ig.-21
(e)