Flashlight Photometer

1. Unboxing and Basic Familiarization with the Equipment

1.1 Key Technical Specifications

Parameters	Note
Measurement Parameters	Flash frequency, flash duration, effective luminous intensity, instantaneous maximum/minimum luminous intensity, average luminous intensity
Illuminance Measurement Range	0.1 lx–20000 lx, 4-range automatic range selection
Optical Measurement Accuracy	Class A/Level 1 (Compliant with JJF 1330-2011)
Sampling Rate	1 kS/s, 2 kS/s, 5 kS/s, 10 kS/s, 20 kS/s, 50 kS/s, 100 kS/
Test Time Range	100 ms to 10 sec
Temporal resolution	10 μs

1.2 Unboxing Inspection and Verification of Accessories

1.2.1 Unpacking and Visual Inspection

When unpacking the device, handle it gently to avoid scratching the outer casing with sharp tools. After unpacking, first inspect the exterior of the device to ensure there is no visible deformation or dents, and that the buttons are not damaged or loose. If you notice any abnormalities with the device or its accessories, do not turn it on. Please contact us immediately.

1.2.2 Main Unit and Accessories

Number	Note
①	PM400F Photometer
②	Light-Blocking Tube
③	USB Cable
④	Power Adapter

Figure 1

Download links for the digital user manual, software, warranty card, and other materials have been sent via email. Please download them as soon as possible. If you missed the email, please feel free to contact us to request the download links again.

1.4 Applicable Test Scenarios

Aerospace sector: Aircraft navigation lights, anti-collision lights (compliant with HB6490-1991), and aviation obstruction lights (compliant with MH/T 6012-1999).

Transportation Sector: Traffic warning lights, navigation lights (compliant with JTT 761—2022).

Other fields: flare bombs, signal flares, pulsed LEDs, pyrotechnic explosives, and other pulsed light sources (compliant with ECE R65 and JJF1330-2011).

2. Precautions for Use

2.1 Safety Operating Procedures

2.1.1 Power Supply Safety

You must use the included DC 5V/1A power adapter. Never use a power source with incompatible voltage or current, to prevent damage to the device.

2.1.2 Environmental Safety

It is strictly prohibited to operate equipment in explosive atmospheres or areas where flammable and explosive materials are stored, as the operation of electrical equipment may cause safety incidents.

Avoid using the device in environments with strong electromagnetic interference (such as near high-power motors or radar systems) to prevent affecting the accuracy of measurement data.

The surface of the equipment may become slightly warm during operation. Avoid covering it with foreign objects, ensure adequate ventilation, and prevent damage caused by overheating.

2.2 Contraindications for Use

The equipment has been calibrated before leaving the factory. Users are strictly prohibited from performing calibration operations on their own, as this may compromise measurement accuracy.

Do not remove any exterior components from the device. High voltage is present inside the device, and disassembly by non-professionals may result in personal injury or damage to the device.

The probe surface is a precision optical component; do not touch or scratch it with your hands, and avoid wiping it with corrosive cleaning agents.

2.3 Environmental Requirements

Operating Environment Conditions: Temperature: 18°C to 30°C; Humidity: 35%RH to 75%RH.

Storage Conditions: Temperature: -20°C to 50°C; Humidity: ≤90% RH.

Testing must be conducted in a darkroom, where stray light must be ≤0.01 lx to prevent ambient light from interfering with the measurement results (this is particularly important during low-light measurements).

The test distance between the light source under test and the detector must be adjusted according to the light source’s intensity (for example, the distance may be appropriately increased for a strong light source), and the light-emitting surface of the light source must be aligned directly with the center of the detector’s window.

2.4 Other

For matters not covered in this manual, please proceed with caution or contact us.

3. Hardware Operations

3.1 PM400F Assembly and Wiring

3.1.1 Assembly of the Light-Blocking Cylinder

Number	Note
①	Remove the probe cover
②	Hold the light-blocking cylinder and rotate it clockwise while aligning it with the detector window until it is fully tightened, ensuring there is no play or gaps that allow light to leak through.

Figure 2

Figure 3

3.1.2 Introduction to the PM400F Front Panel and Wiring

Number	Note
①	Touchscreen displaying real-time test data, parameter settings, etc . Note: Do not adjust any parameters without authorization to avoid causing test abnormalities.
②	RS-485 communication port—required when used with a Goniophotomoeter; if you have purchased only the PM400F, you do not need to use this port.
③	USB port; connect to a computer using a USB cable to communicate with the software
④	Power adapter port—please connect the power adapter

Figure 4

Note 1: Please use only the original USB cable to connect the PM400F directly to your computer whenever possible. Do not use other USB extension cables, USB adapters, or similar devices, as they may cause the software to malfunction.

Note 2: The PM400F can be powered via a USB cable; however, in some cases, the USB power supply may be unstable. Therefore, you should also connect the power adapter to ensure a stable power supply. If the power supply is unstable, the device or software may malfunction. We recommend connecting both the USB cable and the power adapter at the same time.

3.2 Laboratory Layout

The PM400F must be used in a darkroom environment. Position the light-emitting surface of the luminaire being tested directly in front of the PM400F probe, for example, at a distance of 3 meters. If the luminaire emits a strong light, the test distance may be appropriately increased.

Please connect the power adapter to the PM400F, connect the PM400F to your computer using a USB cable, and then operate it using the software.

4. Software Operation

4.1 Software Installation

4.1.1 Computer Requirements

Category	Specific Requirements
Operating System	Windows 7/8/10/11 (32-bit or 64-bit)
Hard Drive Space	Free space ≥ 100 MB
API Requirements	At least one USB 2.0 or higher port
Other	You should log in to your computer using an administrator account whenever possible; otherwise, the software may malfunction.

4.1.2 Software Installation

Below are the software and drivers for the PM400F. Simply double-click each one to install it.

Figure 5

Open “Device Manager” on your computer. If you see “LISUN GROUP Devices” > “Lisun FLASHLIGHT TESTER,” the software and driver have been installed successfully.

Figure 6

4.2 Software Settings

4.2.1 Calibration

Important Note: The PM400F has been calibrated before shipment; please do not perform any calibration procedures.

Figure 7

4.2.2 System Configuration

Click “System Configuration.”

Figure 8

Communication Settings: Select “USB” as the connection type, click the device serial number drop-down menu, and the device number will be automatically retrieved (make sure the device is powered on and connected).

Data Processing and Display.

Number	Note
①	Waveform display range: Default “Auto Select”; number of display cycles set to 8
②	Method for Calculating Effective Illuminance: The default selection is “Blondel-Rey-Douglas” (recommended by the International Civil Aviation Organization and compliant with relevant standards).
③	Remove Background Light: Check this box to eliminate the effect of ambient stray light on the measurement.
④	Pulse train dark time: Default 20 ms (times longer than this are not considered pulse trains)

Figure 8.1

Storage Settings.

Number	Note
①	Check the box to enable the auto-save feature
②	Select a save location
③	Test File Naming Conventions

Figure 9

Note: Files saved automatically are in FLM format and can only be opened and viewed using the PM400F software.

4.2.3 Test Setup

Number	Note
①	Click “Test Settings”
②	Photometric type: Select “illuminance” or “luminous intensity” based on testing requirements (luminous intensity is commonly used for testing navigation lights and obstruction lights).
③	Test Distance: Enter the actual distance (in meters) from the probe surface to the light source being measured. This value must match the actual setup (e.g., 3 m).
④	Sampling rate: The default is 20 kS/s. If you are testing light sources with high flash frequencies and short durations (such as pulsed LEDs), you can set it to 50 kS/s or 100 kS/s.
⑤	Sampling duration: 1 to 200 seconds; must be longer than the flash cycle (recommended settings are 5 or 10 seconds to balance test efficiency and data integrity)
⑥	Range: Set to “Auto”
⑦	Test Start Mode: The default setting is “Auto Start.” For special samples (such as flash grenades), you can select “Automatic Signal Trigger” and set the trigger threshold (which must be higher than the background light signal).
⑧	If you set a warm-up time, and the light source under test requires a certain amount of time to stabilize after being turned on, you can set the appropriate warm-up time. A value of 0 means no warm-up.
⑨	Interval between consecutive tests; if consecutive testing is required, the time interval between two tests

Figure 10

4.3 Start/Stop Test

4.3.1 Startup Test

For unknown samples, click to perform a “single test,” then wait for the sample to emit a light signal, and the software will automatically perform the test.

For standard samples, testing can begin immediately after the sample is illuminated. Click to perform a “Single Test” or “Repeat Test.”

Figure 11

4.3.2 Stopping the Test

After the test is complete that day, you can unplug the PM400F power adapter or turn off the outlet switch. Then, shut down the computer to completely cut off power to the PM400F.

4.4 Processing Test Reports

Click to enter sample information.

Figure 12

You can set different display time intervals to zoom in or out on the light intensity curve.

Figure 13

Click “Save As.”

Figure 14

You can save the test data as a CSV or TXT file.

Figure 15

If your computer is connected to a printer or has a PDF printer installed, click “Print” to print the test report.

Figure 16

The test report template is shown below.

Figure 17

4.5 Analysis of Key Parameters in Test Reports

The results for the following key parameters all comply with the definitions in the relevant standards:

Flash Duration: Measured in “ms,” this value represents the duration of the flash from start to finish (e.g., 0.26 ms).

Flash frequency: Measured in “flashes per minute,” this indicates the number of flashes per minute (e.g., 61 flashes per minute).

Effective luminous intensity: Measured in “cd”; the equivalent luminous intensity value obtained using a selected calculation method (such as the Blondel-Rey-Douglas method).

Average luminous intensity: Measured in “cd”; the average luminous intensity over one flash cycle.

Maximum/Minimum Luminous Intensity: Measured in “cd,” representing the peak and valley values of luminous intensity within a single cycle.

5. Routine Maintenance and Care of Equipment

5.1 Routine Maintenance

Keep the darkroom control room clean and dust-free to prevent dust from entering the equipment. If there is surface dust on the equipment, wipe it off with a dry, soft cloth.

Avoid exposing the darkroom to high humidity for extended periods; keep a dehumidifier on hand if necessary.

5.2 Cleaning the Photometric Probe

If the darkroom cannot be kept dust-free, clean the photosensitive surface of the photometer probe regularly (for example, once a month) based on actual conditions to prevent dust from accumulating and affecting test accuracy.

When cleaning, please use a professional lint-free cloth to remove dust and prevent scratches on the device.

5.3 Long-Term Decommissioning and Maintenance

5.3.1 Equipment Cleaning and Protection

Thoroughly clean the surface, and store the PM400F and connecting cables separately in their own packaging.

5.3.2 Monthly Power-On

Conduct a test by powering the system on once a month to ensure it is operating normally.

Troubleshooting and Resolving Common Issues

6.1 Communication Failure (Software Cannot Recognize the Device)

Fault Symptoms	Possible Causes	Troubleshooting Methods
“Lisun FLASHLIGHT TESTER” is not listed in Device Manager	The driver is not installed or the installation failed.	Reinstall the driver and make sure the installation is successful.
The driver installed successfully, but the software cannot connect.	Unstable or insufficient power from the USB cable	Please connect the power adapter at the same time to ensure a stable power supply.

6.2 Software Crashes on Startup

Fault Symptoms	Possible Causes	Troubleshooting Methods
The software does not respond when double-clicked, or an error message appears	System environment incompatibility, incomplete software installation	1. Verify that your operating system meets the requirements (Windows 7 or later); 2. Uninstall the software and reinstall it (run the installer with administrator privileges); 3. Turn off your computer’s firewall and antivirus software, then try again

6.3 High/Low Measurement Values

Fault Symptoms	Possible Causes	Troubleshooting Methods
The data is generally on the high side	Background light and probe contamination not accounted for	1. Check the “Remove Background Light” option in the software and retest; 2. Clean the light-sensitive surface of the photometer probe; 3. Check for stray light in the darkroom and ensure it meets the requirements.
The data is generally on the low side	Incorrect test distance setting, improper range selection	1. Verify the test distance to ensure that the software settings match the actual setup; 2. Switch to a higher range (e.g., from Range 1 to Range 2) and retest; 3. Check whether the sample has stabilized; if not, extend the warm-up time.

6.4 Displays “—-” (out of range)

Fault Symptoms	Possible Causes	Troubleshooting Methods
During testing, the PM400F displays “—-”	The light source intensity exceeds the current range	1. Change to a wider measurement range (e.g., switch from auto-range to range 4); 2. Increase the test distance (e.g., from 3 m to 5 m); 3. If the measurement still exceeds the range, please contact us to purchase an attenuator.

6.5 Troubleshooting Error Codes

Troubleshooting Codes	Fault Description	Possible Causes	Troubleshooting Methods
Insufficient data returned! (52)	Incomplete data transfer	Insufficient power from the USB port	1. Replace the USB port on the back of the computer; 2. Shorten the USB cable (≤5 meters)
Insufficient return data! (49)			Ibid.
Insufficient return data! (5b)		The USB cable is too long	Replace the USB cable with one that is 5 meters or shorter, and reconnect it.