TRH 8706N User manual

OPERATION MANUAL
Model:
Model:8903/8904/8906
POCKET
PSYCHROMETER
8706
8716
8706N

Thank you very much for purchasing
this psychrometer!
This unique meter is designed as pocket
size, battery operated for Humidity, Dry
Bulb, Dew Point, Wet Bulb, External
Temperature & Temperature Differential
measurement. The sensor is also
specially protected by tunable cap.
The psychrometer is a micro processor-
based design. Amust device for HVAC
engineers use. No need to whirl the
meter or refer to the chart. Easy to get
Wet Bulb/ Dry Bulb and Dew Point
temperature quickly!
Features :
1
INTRODUCTION
Triple LCD digital display.
T1-T2 & T2-DP function.(Model:8716)
Data Hold to capture readings.
Pocket size, easy to fit in pocket.
Low battery indication.
Fast response .
Accurate reading .
Maximum record function .
Minimum record function.
Dew Point calculated in seconds.
(Model:8706, 8716)
Wet Bulb calculated in seconds.
(Model:8706, 8716)
Microprocessor circuitry for reliability.
Auto power off time frame selectable.
Disable power off.
Tunable cap to protect sensor.
External Temp. probe.

2
The meter x 1
Battery x 2 (AAAsize )
Operation manual
White plain box / gift box
Optional accessory :
External temperature probe :
P/N: VZ87P6AZ
Calibration salt bottles :
(33% and 75%)
P/N: VZ0033AZ1 , VZ0075AZ1
Hard carry case :
P/N: VM68706B
MATERIAL SUPPLIED
WARNING
IMPORTANT:
CLOSE OPEN
External probe port
BE SURE TO OPEN THE SENSOR
PROTECTION CAP BEFORE STARTING
THE MEASUREMENT IN ORDER TO
GET ACCURATE VALUE FOR ALL
MODELS.
This package contains:

HOLD
MX/MNMX/MN
oo
C/ F
MODE
RESETRESET
5) RESET Key
- Reset Min/Max memory
6) MN/MX Key
- Display minimum value of memory
from power on to the moment.
- Display maximum value of memory
from power on to the moment.
1) Key
- Power on/off
oo
2) C/ F Key
-Switch between
o
display of C
o
and F
3) MODE key
- N/A
4) HOLD Key
- Hold display
- + HOLD = Non-Sleep mode (The
default setting is auto-sleep in 5 min.)
3
CONTROLS AND INDICATORS
Db
Ex.
OC
OF
LCD DISPLAY
RH%
Dry Bulb
External
Temperature
Model:8706N

Db
DP
Wb
Ex.
OC
OF
LCD DISPLAY
RH%
Dry Bulb
Dew Point
Wet Bulb
External
Temperature
Model:8706
HOLD
MX/MNMX/MN
oo
C/ F
MODE
RESETRESET
1) Key
- Power on/off
5) RESET Key
- Reset Min/Max memory
- Wb and Ex mode switch (Press to
display only while external probe is
plugged.)
6) MN/MX Key
- Display minimum value of memory
from power on to the moment.
- Display maximum value of memory
from power on to the moment.
oo
2) C/ F Key
-Switch between
o
display of C
o
and F
3) MODE key
-Switch between
display of Db &
DP
(Db=Air Temp.)
4) HOLD Key
- Hold display
- + HOLD = Non-Sleep mode (The
default setting is auto-sleep in 5 min.)
4

5
LCD DISPLAY
1) ON/OFF key
-Power on/off
oo
3) C/ F key
-Switch between
oo
C and F
Model:8716
2) key
-Switch between
,DP and T1.
( T=T1-T2,
T1=Air Temp.
T2=ExternalTemp.)
T/DP
T1
T
5) key
-Switch between , WB and T2.
( =T2-DP,T2=ExternalTemp.)
/WB
T2
6) key
- Reset Min/Max memory.
- Display minimum value of memory
from power on to the moment.
- Display maximum value of memory
from power on to the moment.
Air Temp.
RH%
Dew
Point
T1-T2
Wet Bulb
External
Temperature
T2-DP
4) HOLD Key
- Hold display
- ON/OFF + HOLD = Non-Sleep mode.
Non-sleep time is selectable from 2, 5,
10, 20, 40 to 60 min. (The default
setting is auto-sleep in 10 min.)
HOLD
T/DP
T2 T1
/WB
ON/OFFON/OFF
oo
C/ F
RESETRESET
MX/MNMX/MN
RESETRESET
MX/MNMX/MN

Fig. A
6
Unit will turn itself off after 5 minutes
(8706N, 8706) or 10 minutes (8716).
To override Auto Power Off function,
press + HOLD (8706N, 8706) or
ON/OFF + HOLD(8716) while the meter
is off. When " n" appears (See Fig.A),
release HOLD button. Meter is now in
Non-Sleep Mode.
(1) Turning on the protective sensor cap
in counterclockwise direction.
(2) Turn meter on by pressing (8706N,
8706) or ON/OFF(8716) button.
(See Fig.B)
(3) Press C/F key more than 1 sec. to
convert reading to desired unit.
Both temperature and relative
humidity measurement will display
simultaneously.(See Fig.C)
Fig. B
AUTO POWER OFF
(SLEEP FUNCTION)
MODE OPTIONS
Db
DP
Wb
Ex.
OC
OF
8706
Fig. C
8716
For 8716, the auto power off time frame
could be selectable from 2, 5, 10, 20,
40 to 60 minutes.

Press "HOLD" button until (HLD)
appears in display.
The current reading is now held and will
not change until Hold function cancelled.
(See Fig.D).
Press "HOLD" button again to cancel
Hold function. Hold function can be
used on humidity, dew-point, dry bulb/T1
, Ext. Temp./T2, wet bulb and
temp. Difference.
DATA HOLD FUNCTION
7
Wb
OC
Db
8706
Fig. D
PARTIAL HOLD FUNCTION FOR 8716
While in normal mode, press "HOLD"
+ ,only the T1, RH will be held.
Press "HOLD"again to release.
While in normal mode, press "HOLD"
+ ,only the T2 will be held.
Press "HOLD"again to release.
T2
/WB
T/DP
T1
Press MODE button until "DP" appears
on display. Select to display dew point
or dry bulb (air temp.) in any mode while
the unit is on. See Fig. E
DEW POINT FUNCTION
8706:
8706N isn't equippedwith this function.

WET BULB FUNCTION
Turn the meter on by pressing button.
User will see "Wb" temperature
indicated on the display. See Fig.E
8706
8716
/WB
T2
Press until Wbappear on the
LCD.User will see"Wb" temperature
indicated on thedisplay. See Fig.E1
8706N isn't equippedwith this function.
Fig. E Fig. E1
Press button until "DP" appears
on display. Select to display dew point,
T1( air temp.) or delta T(T1-T2) in any
mode while the meter is on. See Fig. E1.
8716:
T/DP
T1
Wb
OC
DP
Ex. TEMPERATURE FUNCTION
Plug the external probe into the meter.
Unit will now display external probe
temperature. See Fig.F1
8706N
Plug the external probe into the meter.
Short press RESET button until "Ex"
appears on display. Unit will now display
external probe temperature. See Fig.F2
8706
8

9
Fig. F1
Db
Ex.
OF
OC
DP
Ex.
Fig. F2 Fig. F3
8716
Plug the external probe into the meter.
Press button until "T2" appears
on display. Unit will now display external
probe temperature. See Fig.F3
T2
/WB
Remark: For 8706 and 8716, If the probe
isn't plugged in meter, "Ex"or "T2" won't
appear on display even pressing the
RESET or key.
T2
/WB
MIN./MAX. FUNCTION
(1) Press and hold MN/MX (8706N, 8706)
or (8716) button until (MIN)
appears on display.(See Fig.G)
Display is now showing minimum
humidity and temperature readings
in memory.
(2) Press and hold MN/MX(8706N,8706)
or (8716) button again until (MAX)
appears on display. (See Fig.H)
Display is now showing maximum
humidity and temperature readings in
memory.
RESETRESET
MX/MNMX/MN
RESETRESET
MX/MNMX/MN

Note: Remember Low Batteries will
tend to give inaccurate readings, so
make sure you have enough power.
WARNING: While checking MIN/MAX
value for EX,T2, and , don't replace
probe otherwise you will get error code
displayed.
If you don't plug the probe into socket
before turning the meter on, the error
code will also appear when you check
MIN/MAX value.
T
10
Fig. G
8706
OC
Ex.
DP
(3) To return to current temperature
and humidity readings press and
hold MN/MX or button until Min
or Max disappear from display.
(4) Press RESET or button more than
two seconds to clear current reading
from memory.
RESETRESET
MX/MNMX/MN
RESETRESET
MX/MNMX/MN
T2
DP
Fig. H
8716

&
is calculated bysubtracting the T2
(Ex.temp.) from T1(Air temp.).
is calculated bysubtracting the DP
(dewpoint) from T2(Ex. temp.).
(1) Press button until appears
on display.(See Fig.J)
T/DP
T1
Fig. J
These functions areonly for 8716model.
11
T2
Fig. K
DP
LOW-BATTERY
Battery symbol will appear on display
at right top corner when the power is
low. Failure to replace batteries will
have an effect on the accuracy of the
readings.
OC
Ex.
DP
T2
/WB
(2) Press button until appears
on display. (See Fig.K)
1. Open the battery cover on the rear
side.
2. Remove the expired batteries.
3. Insert new 2pcs AAA batteries and
make sure the batteries are in correct
polarity. Then, put on the cover.

CALIBRATION
12
1. Turnthe meter off and plugthe sensor
into 33% saltbottle. Press "ON/OFF
+ C/F " keys morethan one sec.to
enter calibration mode.
2. "32.8%" will flashon LCD and DP,
WB is displayedas "---.-" that means
the values areinvalid in the calibration
process. After30 min, the flashing will
stop to indicatethe procedure is
finished.
3. Move thesensor to 75% salt bottle
and press "MN/MX"(8706), " "
(8716) more thanone sec. to enter
75.3% calibration. "75.3%" will flash
on LCD.
4. Flashing stopsafter 30 mins, up to
now the wholecalibration is
completed and thecalibration data
has been savedin memory.
RESETRESET
MX/MNMX/MN
Note:
a. You can exit calibration procedure
without saving bypressing "ON/OFF"
key before step4. Atstep 4, pressing
"ON/OFF" key toexit calibration.
b. Autopower off is disabled in
calibration mode.
c. To get highaccuracy, calibration
should be operatedat 23 degreeC.
d. If thereading is outof 75.3% 0.5%
at step 4,it means thecalibration is
failed. See troubleshooting3.
TROUBLESHOOTING
Power on but no display
A) Make sure the time of pressing
ON/OFF key is more than 0.1 sec.
B) Check the batteries are in place and
making good contact and correct
polarity.

13
Er 1
Circuit error in RH measurement
channel, return the meter to the store
for repairing.
A) Check whether the low battery
indicator displayed before display
disappears, if yes, replacing a new
battery.
B) Check whether sleep mode is
active. If yes, pressing + HOLD
or ON/OFF+HOLD key to disable
auto power off function.
Er 2
Circuit error in Internal temperature
measurement channel, return the
meter to the store for repairing.
C) Replace a new battery and try
again.
D) Remove the batteries for one min.
And then put back for second try.
No Display
Er 3
Circuit error in reference resistor
channel, return the meter to the store
for repairing.
.
Er 4
Internal temperature is out of the
range.
Er 5
External temperature is out of the
range.

Note:
a. Dry Bulb temperature means
air (Internal) temperature.
Dew point & Web Bulb are calculated
from internal temperature.
14
SPECIFICATION
oo
Temp. range : -20~ +50 C(-4~ 122 F)
RH% range : 0~100%RH
Wet bulb range : (8706, 8716)
oo
-21.6 ~ 50.0 C(-6.88~122 F)
Dew point range : (8706, 8716)
oo
-78.7 ~50.0 C (-109.7~122 F )
External temp. range :
oo
-20~ 70 C (-4~158 F)
Optional accessory: External temp.
Probe VZ87P6 AZ
Response time : 60 seconds typical.
Pocket size :
24.7(H) x 48.4(W) x178.5mm(L)
Extension cable length:
Approx. 1.2M (with phone jack 2.5 mm)
Probe (with handle):15cm (approx.)
Power:2 x 1.5V AAA battery
o
Accuracy: RH%: 3% at 25 C
o
o
Temperature: 1 F (0.6 C)
b. When the meter is on, pluggin
in an external probemight cause
" ER 5 " error in min. or max mode
of ext. Temperature,T2-T1 andT2-
dp. pressing "RESET"key could
solve above question.

15
Authorization must be obtained from the
supplier before returning items for any
reason. When requiring a RA(Return
Authorization) , please include data
regarding the defective reason, the
meters are returned along with good
packing to prevent any damage in
shipment and insured against possible
damage or loss.
RETURN AUTHORIZATION
Proof of purchase is required for
warranty repairs. Warranty is void if the
meter has been opened .
The meter is warranted to be free from
defects in material and workmanship
for a period of one year from the date
of purchase. This warranty covers
normal operation and does not cover
battery, misuse, abuse, alteration,
tampering, neglect, improper maintenance
or damage resulting from leaking batteries.
WARRANTY

15
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Measuring / Testing Instruments !
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