TRIPLETT LT68 Datalogging Light Meter User Manual

: June 6, 2024
: TRIPLETT

TRIPLETT LT68 Datalogging Light Meter User Manual

Introduction

Congratulations on your purchase of the Triplett LT68 Digital Light Meter. The LT68 measures illuminance in Lux and Foot candles (Fc).
The LT68 is a Datalogger and includes a PC interface and WindowsTM compatible software for downloading data. Up to 16,000 readings can be stored on the meter for download to a pc and 99 readings can be
stored and viewed directly on the meter’s LCD display. This meter is shipped fully tested and calibrated and, with proper use, will provide years of reliable service.

Description

Meter Description

Sensor Cable Plug
Micro USB Port
LCD Display
Upper Function Button Set
Lower Function Button Set
Power Button
Light Sensor

Note: Battery compartment on rear of meter

Display Description

Clock Setting Modes
Clock Display
Relative Mode Icon
Auto Power OFF (APO) Icon
Low Battery Icon
Data Hold Icon
Peak Hold Modes
Range Indicators
Unit of Measure
Digital Display
Bargraph Display
Data Download to PC Icon
PC Serial Connection Established
Memory Address Number
USB PC Connection Icon
Memory Icon

Operation

Meter Power

Press the Power button to turn the meter ON or OFF
If the meter does not switch on when the power button is pressed or if the low battery icon is displayed on the LCD, replace the battery.

Auto Power Off (APO)

The meter is equipped with an automatic power off (APO) feature that turns the meter off after 20 minutes of inactivity. The icon appears while APO is enabled.
To disable the APO feature, simultaneously press and release the RANGE/APO and REC/SETUP buttons. Press and release again to re-activate the APO feature.

Unit of Measure

Press the UNITS button to change the unit of measure from Lux to Fc or from Fc to Lux

Range Selection

Press the RANGE button to select the measurement range. There are four (range) selections for each unit of measure. The range icons will appear to identify the range selected.

Taking a Measurement

Remove the sensor’s protective cap to expose the white sensor dome
Place the sensor in a horizontal position under the source of light to be measured
Read the light level on the LCD display (numerically or with the bargraph).
The meter will display ‘OL’ when the measurement is outside of the meter’s specified range or if the meter is set to the wrong range. Change the range by pressing the RANGE button to find the best range for the application.
Replace the protective sensor cap when the meter is not in use.

Data Hold

To freeze the LCD display, momentarily press the HOLD button. ‘MANU HOLD’ will appear on the LCD. Momentarily press the HOLD button again to return to normal operation.

Peak Hold

The Peak Hold function allows the meter to capture short duration light flashes. The meter can capture peaks down to 10mS in duration.

Press the PEAK button to activate the Peak Hold feature. “Manu” and “Pmax’’ will appear on the display. Press the PEAK button again and “Manu” and “Pmin” will appear. Use ‘Pmax’ to capture positive peaks. Use ‘Pmin’ to capture negative peaks.
When the peak has been captured, the value and associated time will remain in the display until a higher peak is recorded. The bargraph display will remain active displaying the current light level.
To exit the Peak Hold mode and return to the normal operating mode, press the PEAK button a third time

Maximum (MAX) and Minimum (MIN) Reading Memory

The MAX-MIN function allows the meter to store the highest (MAX) and lowest (MIN) readings.

Press the MAX-MIN button to activate the feature. “Manu” and “MAX” will appear on the display and the meter will only display the highest reading encountered.
Press the MAX-MIN button again. “Manu” and “MIN’ will appear on the display and the meter will only display the lowest reading encountered.
When the MAX or MIN has been captured, the value and associated time will remain in the display until a higher value is recorded. The bargraph display will remain active displaying the current light level.
To exit this mode and return to the normal operating mode, press the MAX-MIN button a third time.

Relative Mode

The Relative Mode function allows the user to store a reference value in the meter. All displayed readings will be relative to the stored reading.

Take the measurement, and when the desired reference value is displayed, press the REL button.
“Manu” will appear on the LCD display.
All subsequent readings will be offset by the by an amount equal to the reference level. For example, if the reference level is 100 Lux, all subsequent readings will equal the actual reading minus 100 Lux.
To exit the Relative Mode, press the REL button.

LCD Backlight

The meter is equipped with a backlight feature that lights up the LCD display.

c. Press the backlight button to activate the backlight.
d. Press the backlight button again to switch the backlight off. Note that the backlight will turn off automatically after a short period of time in order to save battery energy.
e. The backlight function uses extra battery energy. To conserve energy, use the backlight feature sparingly.

Clock and Sample Rate Setup

In this mode, the ▲ and ▼ arrow buttons will allow adjustment of the selected (flashing) digits.
The ◄ and ► buttons will scroll to the next or previous selection.

Power the meter, then press and the REC/SETUP and UNITS buttons simultaneously to enter the Setup mode. The hours display will flash.
Adjust and step through each selection as needed.
Press and hold the REC/SETUP and UNITS buttons simultaneously to exit the Setup mode. The order of selection with the flashing (icon) is:

Hour (0 to 23) 12:13:14 (Time)
Minute (0 to 59) 12:13:14 (Time)
Second (1 to 59) 12:13:14 (Time)
Sample Rate (00 to 99
seconds) 02 (Sampling)
Month (1 to 12) 10310 (Day)
Day (1 to 31) 10310 (Day)
Day of the week (1 to 7 10310 (Day) (Sunday = 1) Year (00 to 99) 2013 (Year)

99 Point Memory

Up to 99 readings can be stored manually for later viewing directly on the meter’s LCD. This data can also be transferred to a PC using the supplied software program.

With the meter ON, press the REC button momentarily to store a reading
The MEM display icon will appear with the memory address number (01 -99)
If the 99-reading memory is full, the MEM icon and memory location number will not appear
To view stored readings, press and hold the LOAD button until the MEM display icon appears alongside the memory address number.
Use the up and down arrow buttons to scroll through the stored readings.
To clear the data, press and hold the REC/SETUP and LOAD buttons simultaneously until ‘CL’ appears in the memory location field on the LCD

16,000 Point Datalogger

The LT68 can automatically record up to 16,000 readings in its internal memory. To view the data, the readings must be transferred to a PC via the supplied software.

Using the SETUP mode, set the time and sample rate. The default sample rate is 1 sec.
To begin recording, Press and Hold the REC button until the MEM display icon begins blinking. Data will store at the sample rate while the MEM icon is blinking.
To stop recording. Press and Hold the REC button until the MEM icon disappears.
If the memory is full, OL will appears as the memory number.
To clear the memory, with the meter off, press and hold the REC button and then press the power button. “dEL” will appear in the display. Release the REC button when “MEM” appears in the display, the memory has been cleared.

USB PC Interface

Description

The LT68 meter can be connected to a PC via its USB interface. A USB cable, along with
WindowsTM software, is included with the meter. The software allows the user to:
Transfer previously stored readings from the meter’s internal memory to a PC
View, plot, analyze, store, and print readings data
Remotely control the meter via virtual software buttons
Record readings as they are taken. Subsequently, printing, storing, analyzing, etc. the readings data

Meter to PC Connection

The supplied USB cable is used to connect the meter to a PC. Connect the smaller connector end of the cable to the meter’s interface port (located under the tab at the left-hand side of the meter). The larger
connector end of the cable connects to a PC USB port.

Maintenance

Cleaning

The Meter and its sensor can be cleaned with a damp cloth. A mild detergent may be used but avoid solvents, abrasives, and harsh chemicals.

Battery Installation / Replacement

The battery compartment is located on the back of the meter. The compartment is easily accessed by pressing and sliding the rear battery compartment cover off of the meter in the direction of the arrow.
Replace or install the 9V battery and close the battery compartment by sliding the compartment cover back onto the meter.

Never dispose of used batteries or rechargeable batteries in household waste. As consumers, usersare legally required to take used batteries to appropriate collection sites, the retail store where the batteries were purchased, or wherever batteries are sold.

Disposal: Do not dispose of this instrument in household waste. The user is obligated to take end-of-life devices to a designated collection point for the disposal of electrical and electronic equipment.

Other Battery Safety Reminders

Never dispose of batteries in a fire. Batteries may explode or leak.
Never mix battery types. Always install new batteries of the same type.

Storing

When the meter is to be stored for a period of time, please remove the battery and affix the sensor’s protective cover. Avoid storing the meter inareas of extreme temperature and humidity.

Specifications

Range Specifications

General

Specifications

Warranty

Triplett / Jewell Instruments extends the following warranty to the original purchaser of these goods for use. Triplett warrants to the original purchaser for use that the products sold by it will be free from defects in workmanship and material for a period of (1) one year from the date of purchase. This warranty does not apply to any of our products which have been repaired or altered by unauthorized persons in any way or purchased from unauthorized distributors so as, in our sole judgment, to injure their stability or reliability, or which have been subject to misuse, abuse, misapplication, negligence, accident or which have had the serial numbers altered, defaced, or removed. Accessories, including batteries are not covered by this warranty