Kewtech KEW337 - User Manual

I. Safety Information
Read the following safety information carefully before
attempting to operate or service the meter.
Use the meter only as specified in this manual; otherwise,
the protection provided by the meter may be impaired.
 Environment Conditions
 Altitude up to 2000 meters
 Relative humidity 90% max.
 Operation Ambient 0 to 40°C
 Maintenance & Clearing
 Repairs or servicing not covered in this manual should
only be performed by qualified personnel.
 Periodically wipe the case with a dry cloth. Do not use
abrasives or solvents on this instrument.
 Safety symbols
Comply with EMC
When servicing, use only specified replacement
parts.


II、General Description
Thank you for using our Light Meter. To ensure that you can
get the most from it, we recommend that you read and
follow the manual carefully before use. The Light Meter has
been designed, manufactured, and delivered under strict
quality control criteria by a factory certified.
 Easy to use
 Automatic zero
 Automatic range
III、Specifications
Measuring ranges:
0.00 to 39.99/399.9/3999/39990 lx
0.000 to 3.999/39.99/399.9/3999 fc
automatic/manual selection of range
Resolution: 0.01 lx ~ 10 lx ; 0.001 fc ~ 1 fc
Accuracy: ±3﹪rdg ±5 dgts
Temperature characteristics: ±0.1﹪/ °C
Response time: 0.5 sec.
Light detector: Si Photodiode
Operation temp./ humidity:
0°C ~ 40°C (32°F ~ 104°F)，0 ~ 80﹪RH
Storage temp./ humidity:
-10°C ~ 50°C (14°F ~ 122°F)，0 ~ 70﹪RH
Over range: "----" display
Power supply:
one 9V battery，006P or IEC 6F22 or NEDA 1604
Power life: Approx. 170 hours (Alkaline battery)
Dimensions:
196(L) X 54(W) X 33(H) mm
7.7(L) X 2.1(W) X 1.3(H) inch
Weight: Approx. 180g
Accessories: 9V battery, instruction manual
IV、Name and functions
○
1
Light detecting surface
○
2
Protect cover
○
3
LCD display
○
4
Power button
○
5
CAL button: quick enter measuring mode
During the measuring mode, press CAL button and the
value of zero will be auto-displayed.
○
6
HOLD button:
The user may hold the present reading and keep it on the
LCD display by pressing the “HOLD” button. To release the
held data operation by pressing it again. The user can
press the button when the value is hard to read, such as
measuring in the dark place.
○
7
fc/lx selector button
○
8
Range selector button:
This button is used to select automatic range and manual
range. Manual range enables an arbitrarily four range to be
set. If a fixed range is used, measuring values will
response quickly. The user can read easily.
The range configuration is as follows:
Auto , 40 , 400 , 4000 , 40000 lx
Auto , 4 , 40 , 400 , 4000 fc
○
9
Battery cabinet cover
○
10
Indicate low battery voltage
○
11
Measuring readout
○
12
Indicate automatic range mode
○
13
Indicate meter in automatic power off mode
This Light Meter provides an automatic power-off function
in order to avoid using up the battery if you forget to turn
off the power. The meter will power off itself after 30
minutes if no key is operated.
○
14
Indicate data hold
○
15
Unit of illuminance
○
16
Indicate range
Note: 1fc＝10.76lx
V、Operation
Press the power button to turn on the power. Notice that
covering the light-detecting surface with the cap.. will
auto-appear on the LCD display. After appears, the
meter enters the automatic zero adjustment. When automatic
zero adjustment is completed, disappears and “0.00 ”
appears. After confirming the “0.00 ” display, remove the cap
to start measuring.
After the measurement has been completed, press the power
button again to turn off the power, and cover the light-detecting
surface with the cap for protecting against stray light.
Note:
If appears, check the cap to make sure it is on
properly.
Press and hold the HOLD button, and then power on the meter,
release all button to disable the AUTO POWER OFF function.
“ ”symbol will disappear on the LCD display.
VI、Replacement of battery
When the battery voltage drops below the operating voltage ,
a“ “ symbol will appear on the LCD display. In this
case, replace a new battery immediately.
VII、Characteristics of relative
visible-spectrum response
400 500 600 700 800
0
20
40
60
80
100%
Spectral Sensitivity
Wavelength(nm)
R
e
l
a
t
i
v
e
S
e
n
s
i
t
i
v
i
t
y
CIE Photopic Curve
Light Meter
VIII、Precautions on handling
Operating carefully, and do not drop the meter or hit it with a
hard object. Avoid using the meter in a dirty, dusty, or salt-air
area or where there are corrosive gases. If dirt or dust
adhered to the surface of detecting light, will decrease
accuracy of the measuring value. To clean the surface by
wiping with a soft and dry cloth.
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Summary

Safety Information

Environment Conditions

Conditions for meter operation: altitude, relative humidity, and operating ambient temperature.

Maintenance and Cleaning

Instructions for servicing, repairs by qualified personnel, and cleaning with a dry cloth.

Safety Symbols

Explanation of safety symbols such as CE marking and the use of specified replacement parts.

General Description

Specifications

Name and Functions

Operation

Battery Replacement

Handling Precautions

Overview

1. Function Description
2. Usage Features
3. Maintenance Features

This document describes the KEW337 Light Meter, a device designed for measuring illuminance. The meter is engineered for ease of use, featuring automatic zero adjustment and automatic range selection to simplify operation.

Function Description

The KEW337 Light Meter measures light levels in both lux (lx) and foot-candles (fc). It utilizes a silicon photodiode as its light detector, ensuring accurate readings. The device is capable of measuring a wide range of illuminance values, automatically adjusting its sensitivity to provide precise measurements across different lighting conditions.

A key feature of this light meter is its ability to perform automatic zero adjustment. When the device is powered on and its light-detecting surface is covered by the protective cap, it automatically enters a calibration mode. During this process, the LCD display will show "CAL" followed by "0.00," indicating that the meter has successfully adjusted its zero point. This ensures that subsequent measurements are accurate by eliminating any baseline offset.

The meter also incorporates an automatic range selection feature. This means the device will automatically choose the most appropriate measurement range for the detected light level, eliminating the need for manual range selection by the user. This simplifies operation and ensures that readings are always displayed with optimal resolution. However, users also have the option to manually select a specific range if desired, which can be beneficial for specific applications where a fixed range is preferred for quicker response times or consistent readings. The available manual ranges are clearly defined for both lux and foot-candle measurements.

The device includes a "HOLD" function, allowing users to freeze the current reading on the LCD display. This is particularly useful when taking measurements in challenging environments, such as dark places, where it might be difficult to read the display directly. Pressing the "HOLD" button once will capture and display the current value, and pressing it again will release the hold, allowing the display to update with live readings.

For convenience and battery conservation, the KEW337 Light Meter is equipped with an automatic power-off function. If no buttons are pressed for approximately 30 minutes, the meter will automatically shut down. This prevents the battery from draining unnecessarily if the user forgets to turn off the device. This auto-off feature can also be disabled by holding down the "HOLD" button while powering on the meter, which is indicated by the disappearance of a specific symbol on the LCD.

The meter's display provides clear indications of its operational status. It shows the measured illuminance value, the selected unit (fc or lx), and whether the automatic range mode is active. Additionally, it features an indicator for low battery voltage, alerting the user when the battery needs to be replaced. An "Err" message will appear if the protective cap is not properly placed during the initial power-on sequence, prompting the user to check the cap.

Usage Features

Operating the KEW337 Light Meter is straightforward. To begin, the user simply presses the power button to turn on the device. It is crucial to ensure that the light-detecting surface is covered by the protective cap during power-on. This allows the meter to perform its automatic zero adjustment. Once the display shows "0.00," the cap can be removed, and the meter is ready to take measurements.

The "fc/lx" selector button allows the user to switch between foot-candle and lux units, depending on their preference or the requirements of the task. The "RANGE" button provides the flexibility to toggle between automatic range selection and manual range selection. In manual mode, the user can cycle through predefined ranges to suit specific measurement needs, which can be advantageous for applications requiring a consistent measurement scale or faster response times within a known illuminance bracket.

The "CAL" button, when pressed during measurement, will auto-display the zero value, which is useful for quick checks or re-zeroing if needed.

The meter's design emphasizes user convenience, with a clear LCD display that is easy to read. The compact and lightweight form factor makes it portable and suitable for various applications, from industrial settings to environmental monitoring.

Maintenance Features

The KEW337 Light Meter is designed for durability and requires minimal maintenance. Users are advised to periodically wipe the case with a soft, dry cloth to keep it clean. It is important to avoid using abrasive materials or solvents, as these can damage the instrument's casing or display.

The light-detecting surface is a critical component for accurate measurements. If dirt or dust adheres to this surface, it can compromise the accuracy of the readings. Therefore, users should ensure that the light-detecting surface is kept clean by wiping it with a soft and dry cloth. The protective cap should always be used when the meter is not in use to shield the light detector from dust, dirt, and potential physical damage, as well as to prevent stray light from affecting the sensor.

Battery replacement is a simple process. When the low battery indicator appears on the LCD display, it signals that the 9V battery needs to be replaced. The battery cabinet cover can be easily accessed to facilitate this. Using the specified battery type (006P, IEC 6F22, or NEDA 1604 alkaline battery) is recommended to ensure optimal performance and battery life.

Any repairs or servicing not explicitly covered in the manual should only be performed by qualified personnel to ensure the safety and integrity of the device. The meter is designed to comply with EMC standards, and any replacement parts used during servicing should be specified to maintain this compliance. Adhering to these maintenance guidelines will help ensure the long-term accuracy and reliability of the KEW337 Light Meter.

Kewtech KEW337 Specifications