Lutron Electronics HT-305 User manual

pocket type
HUMIDITY METE
R
Model : HT-305
Your purchase of this HUMIDITY METER marks a step forward
for you into the field of precision measurement. Although this
METER is a complex and delicate instrument, its durable structure
developed. Please read the following instructions carefully and
always keep this manual within easy reach.
OPERATION MANUAL

TABLE OF CONTENTS
1. FEATURES..............................................................1
2. SPECIFICATIONS....................................................2
3. FRONT PANEL DESCRIPTION...................................5
3-1 Display.............................................................
.
5
3-2 Power Button....................................................5
3-3 Hold Button......................................................
.
5
3-4 REC Button.......................................................
.
5
3-5 Function Button.................................................5
3-6 Battery Compartment/Cover...............................5
3-7 Probe Input Socket ...........................................5
3-8 Probe Plug .......................................................5
3-9 Probe handle.....................................................5
3-10 Probe head ( Humidity & Temperature )..............5
4. GENERAL MEASURING PROCEDURE...........................6
4-1 Humidity and Temperature measurement.............
.
6
4-2 Dew point measurement......................................6
4-3 Data Hold...........................................................
.
7
4-4 Data Record (Max, Min reading)........................... 7
5. BATTERY REPLACEMENT...........................................12

1. FEATURES
*Humidity + Temperature + Dew point are combined
into one meter, intelligent and professional.
*0.1 %RH resolution for the humidity reading,
0.1 degree resolution for the Temp. reading.
*Wide humidity & temp. measuring range.
*Pocket size with Separate humidity & temp. probe,
easy operation. & remote measurement.
*Fast humidity measuring response time.
*High accuracy and high precision.
*Dew point measurement.
*Just few panel buttons, easy operation.
*Microprocessor circuit assures maximum possible
accuracy, provides special functions and features.
*LCD with two display, easy readout.
*Show the humidity & temperature values on the
LCD display at same time.
*Heavy duty & compact housing case, designed
for easy carry out & operation.
*Records Maximum and Minimum readings with Recall.
*Auto shut off saves battery life.
*Data hold function for freezing the desired value
on display.
*Built-in low battery indicator.
1

2. SPECIFICATIONS
2-1 General Specifications
Circuit Custom one-chip of microprocessor LSI
circuit.
Display LCD size : 44 mm x 29 mm
dual function LCD display.
Measurement Humidity : %RH ( Relative Humidity )
Unit Temperature : or .℃℉
Dew point : or .℃℉
Response Time 5 to 30 seconds typically.
@ Reach the 85% reading value
Temperature Automatic temp. compensation for the
Compensation humidity function.
Data Hold Freeze the display reading.
Memory Recall Maximum & Minimum value.
Sampling Time Approx. 0.8 second.
Power off Auto shut off saves battery life.
Operating 0 to 50 .℃
Temperature
Operating Main instrument : Less than 85% R.H.
Humidity Probe : 0 to 95 %RH.
Power Supply 006P DC 9V battery
( Alkaline or Heavy duty type ).
Power Current Approx. DC 4.6 mA.
Weight 264 g/0.67 LB. @ Battery is included.
Dimension Main instrument :
135x60x33 mm, ( 5.3x2.4x1.3 inch ).
Humidity Sensor Probe :
197 mm ( 7.8 inch ) in length.
Accessories Instruction manual.....................
.
1 PC
Included Humidity probe...........................1 PC
2

2-2 Electrical Specifications (23±5 )℃
Humidity/ Temperature
Range 10 % to 95 % R.H.
Humidity Resolution 0.1 % R.H.
Accuracy 70% RH≧± (3% reading + 1% RH).
< 70% RH
±3%RH.
Range 0 to 50 ,32 to 122 .℃℃℉ ℉
Temperature Resolution 0.1 degree
Accuracy - 0.8 .℃℃
- 1.5 .℉℉
Dew Point
℃Range -25.3 to 48.9℃℃
Resolution 0.1 ℃
℉Range -13.5 to 120.1 .℉℉
Resolution 0.1 .℉
Remark :
*Dew Point display value is calculated from the
Humidity/Temp. measurement automatically.
*The Dew Point accuracy is sum accuracy value of
Humidity & Temperature measurement..
@ Above specification tests under the environment RF Field
Strength less than 3 V/M & frequency less than 30 MHz only.
3

3. FRONT PANEL DESCRIPTION
Fig. 1
3-1 Display
3-2 Power Button
3-3 Hold Button ( ESC Button )
3-4 REC Button ( Enter Button )
3-5 Function Button
3-6 Battery Compartment/Cover
3-7 Probe Input Socket
3-8 Probe Plug
3-9 Probe handle
3-10 Probe head
( Humidity & Temperature )
3-11 Set Button
4

4. GENERAL MEASURING
PROCEDURE
The meter default value are :
*The temperature reading unit is .℃
*The power management is set to auto power
off.
4-1 Humidity and Temperature measurement
1)Plug the " Probe Plug " ( 3-8, Fig. 1 ) into the " Probe
Input Socket " ( 3-7, Fig. 1 ).
2)Power on the meter by pressing the " Power Button "
( 3-2, Fig. 1 ), the LCD shows the unit " %RH " & " "℃
at the same time and measured value will show on
the display ( upper display is Humidity value, the
lower display is the temperature value ) .
3)The meter Temp. display unit is defaulted to " ". If℃
intend to let the meter's temperature unit default to " "℉
, then please refer section 5-1 ( page 9 ).
4-2 Dew point measurement
The procedures of " Dew point measurement " are same
as the above " 4-1 Humidity and Temperature
measurement " except select the " Dew point " function
by pressing the " Function Button " ( 3-5, Fig. 1 ) once,
the LCD will show the unit " DEW " & " ( or ).℃℉
The upper display show the Dew point value, the lower
display show the temperature value.
5

4-3 Data Hold
During the measurement, press the " Hold Button " ( 3-3,
Fig. 1 ) once will hold the measured value & the LCD will
display a " HOLD " symbol.
* Press the " Hold Button " once again will release the data
hold function.
4-4 Data Record ( Max., Min. reading )
* The data record function records the maximum and
minimum readings. Press the " REC Button " ( 3-4, Fig.
1 ) once to start the Data Record function and there
will be a " REC. " symbol on the display.
* With the " REC. " symbol on the display :
a)Press the " REC Button " ( 3-4, Fig. 1 ) once, the
" REC. MAX. " symbol along with the maximum value
will appear on the display.
If intend to delete the maximum value, just press
the " Hold Button " ( 3-3, Fig. 1 ) once, then the
display will show the " REC. " symbol only & execute
the memory function continuously.
b)Press the " REC Button " ( 3-4, Fig. 1 ) again, the
" REC. MIN. " symbol along with the minimum value
will appear on the display.
If intend to delete the minimum value, just press
the " Hold Button " ( 3-3, Fig. 1 ) once, then
the display will show the " REC. " symbol only &
execute the memory function continuously.
c)To exit the memory record function, just press the
" REC " button for 2 seconds at least. The display will
revert to the current reading.
6

5. ADVANCED MEASURING
PROCEDURE
When execute the following Advanced
Measuring Procedure should cancel the " Hold
function " and the " Record function " first. The
display will not show the " HOLD " and the " REC "
marker.
a.Hold the " Set Button " ( 3-11, Fig. 1 ) at least two
seconds until the lower display show " COde ", then
release the " Set Button ", the upper display will show
" 1000 ".
*1000 is the password code that allow to execute the
Advanced Measuring Procedure following.
After display show " COde 1000 ", push the " Enter
Button " ( 3-4, Fig. 1 ) once will go to the following b.
procedures.
*If push the " ESC Button " ( 3-3, Fig. 1 ) will escape
the selecting function and return to the normal
measuring display.
b.One by one to press the " Set Button " ( 3-11, Fig. 1 )
once a while to select the two main function that show
on the lower display as :
.......℉Change the Temp , unit℃℉
OFF......
.
Auto power ON/OFF management
7

5-1 Change the Temp , unit℃℉
Use the " Set Button " ( 3-11, Fig. 1 ) to select the main
function to " ", then one by one to press the "℉
Function Button " ( 3-5, Fig. 1 ) a while will determine
the default Temp. unit to or℃℉
@Press the " Function Button ", if the upper display value
show " 0 ", the default Temp. unit is ℃
@Press the " Function Button ", if the upper display value
show " 1 ", the default Temp. unit is .℉
After the function is determined, press the " Enter Button "
( 3-4, Fig. 1 ) to confirm and save the selection data into
memory IC permanently. Press the " Esc Button " ( 3-3.
Fig. 1 ) will revert to normal display screen.
5-2 Auto power ON/OFF
Use the " Set Button " ( 3-11, Fig. 1 ) to select the main
function to " OFF ", then one by one to press the "
Function Button " ( 3-5, Fig. 1 ) a while will determine
the default the power management system is Auto
Power Off enable or disable.
@Press the " Function Button " once, if the upper display
value show " 0 ", it is not Auto Power Off management
( disable ).
@Press the " Function Button " once, if the upper display
value show " 1 ", it is the Auto Power Off management
( enable ).
8