Met One DR-528 Handheld Particle Counter
Specifications
- Model: DR-528
- Manufacturer: Met One Instruments, Inc
- Address: 1600 NW Washington Blvd Grants Pass, Oregon 97526 U.S.A.
- Contact: Tel +1 541-471-7111, Fax +1 541-471-7115, Email: service@metone.com
- Classification: Class I laser product
Product Usage Instructions
Introduction
The DR-528 is a Class I laser product manufactured by Met One Instruments, Inc. It is designed for accurate measurements and easy operation.
Default Settings
The device comes with default settings that are pre-configured for standard operation.
Initial Operation
Before use, review the user manual for safety instructions and guidelines on proper handling.
User Interface
The user interface of the DR-528 is designed to be intuitive and user-friendly.
Operation
About the Measurement
Understand the measurement principles and ensure proper handling during operation.
FAQ
Q: Is it safe to operate the DR-528 without following the specified procedures?
A: No, operating the device without following the specified procedures may result in hazardous radiation exposure. Always adhere to the provided instructions for safe operation.
Introduction
The DR-528 is a full-featured, battery operated, handheld particle counter. The unit will measure particle counts at eight sizes. Default count sizes are 0.3 µm, 0.5 µm, 0.7 µm, 1.0 µm, 2.0 µm, 3.0 µm, 5.0 µm, and 10.0 µm. Each of the eight sizes is user-configurable.
This instrument can store up 15,000 sample events including data from the ambient temperature (AT) / relative humidity (RH) probe. Sample history events can be viewed on the LCD display and downloaded to a computer.
An optional Docking Station complements the DR-528. It charges the unit and increases communication options with RS-485, Ethernet, and WiFi.
Setup
The following sections cover unpacking, layout and performing a test run to verify operation.
Unpacking
Unpack and inspect the contents of the shipping container. Standard items (included) are shown in Figure 1 – Standard Equipment. Optional accessories are shown in Figure 2 – Optional Accessories. Contact the supplier if any items are missing. Any damages incurred during shipping are the responsibility of the carrier. If any damage to the shipment is noticed before unpacking, a claim must be filed with the commercial carrier immediately. You should follow any special unpacking instructions provided by the carrier as you then carefully remove all items from the containers and inspect each component. It is recommended to document and photograph all damaged packages and items before, during, and after unpacking them. Contact Met One Instruments, Inc. (see the Technical Support section at the beginning of this manual) to arrange for any replacement items needed.
ATTENTION:
A Silicon Labs CP210x Driver for the USB connection must be installed before connecting to the USB Type C port.
Driver download weblink: https://metone.com/usb-drivers/
Layout
Figure 3 shows the layout of the DR-528 and provides a description of each of the components.
| Component | Description |
| Power Switch | Switch that turns the DR-528 on or off. Slide up (towards inlet nozzle) to turn on and slide down to turn off. |
| Charging Jack | Input jack for the battery charger. This connection charges the internal battery pack and provides continuous operating power for the unit. |
| Keypad | 2 key membrane keypad. |
| USB C Port | For USB serial communication. |
| Rotary Dial | Multifunction dial (rotate and press). |
| AT/RH Sensor | Integrated sensor that measures ambient temperature and relative humidity. |
| Isokinetic Probe | The isokinetic probe reduces turbulence in the air sample. It attaches over the air inlet nozzle. |
| Bottom Connection | For use with the optional 83529 Docking Station. This is used to charge the unit and transfer data through the docking station. |
Default Settings
The DR-528 comes with the user settings configured as follows
| Parameter | Value |
| Sample Mode | Continuous |
| Count Mode | Cumulative |
| Sample Time | 1 Min |
| Sample Hold Time | 0 seconds |
| Volume (concentration) | CF (particles / ft3) |
| Temperature Units | C |
| USB Baud Rate | 115200 |
Initial Operation
Before operating the DR-528 for the first time, it is recommended that the unit be fully charged. Information regarding charging the battery is found in section 6 of this manual.
Complete the following steps to verify proper operation.
- Slide the power switch up to turn on the power.
- Observe the Startup screen for 2 seconds then the Operate screen (Section 4.3)
- Press START/STOP key. The DR-528 will begin sampling.
- Observe the count levels on the display.
- Turn the rotary dial to view other count levels.
- The unit is ready for use.
User Interface
The DR-528 user interface is composed of a rotary dial, 2 button keypad, and an LCD display. The following table describes keypad functionality. Note some keys have more than one function. 
Operation
The following sections cover the basic operation.
About the Measurement
The DR-528 counts and sizes particles in 8 different size ranges.
Power Up
DR-528 power is controlled by a slide switch located on the left hand side of the unit. Move the power switch to the on position (towards the top of the case) to power up the unit.
The first screen shown on power up is the Startup screen. This screen briefly displays the company logo before loading the Operate Screen.
Operate Screen
The Operate screen displays the sample status, date and time, battery status, sample data, location, temperature, and relative humidity. Figure 4 shows the Operate screen. Four size channels are displayed. Rotate the dial to display additional sizes and the location. 
Sampling
The Operate screen displays current sample information when the unit is sampling (real-time data). Concentration values are time-dependent so these values may fluctuate early in the sample; however, after several seconds the measurement will stabilize.
Sample Status
The top of the Operate screen displays the status of the DR-528 while the unit is sampling. The time remaining is shown at the top left of the screen. A status bar fills with green as time progresses. If a hold time is entered, the status bar will fill yellow during the hold time.
Sample History
Sample history (previous data) can be viewed on the Operate screen when the unit is stopped or sampling. Pressing the knob puts the operating screen in History Mode.
History mode allows you to scroll through previously recorded samples and view the historical data.
In history mode, use the dial action of the rotary knob to scroll through the previous sample data records. Note the red arrows at the top indicate record scrolling mode (see Figure 5). To see additional data for a given record, press down on the rotary dial to enter the data scrolling mode. Using the dial action of the rotary knob will scroll the data up and down and enable users to view the data stored on each channel. Data scrolling mode is indicated by black arrows on the right side of the display (see Figure 6). Press down on the rotary knob again to switch back to record scrolling mode; use the ESC button to exit history mode. A new sample can be started without exiting the history mode by pressing the START button.
- Sample Related Functions
The following sub-sections cover sample related functions. - Starting/Stopping
To start or stop a sample, press the START/STOP key. A sample event can be manually started or stopped from either the Operate screen or the menu. - Sample Mode
The sample mode controls single sample or continuous sampling. Sample modes are discussed in section 5.2.2 - Count Mode
The count mode determines if particle counts are displayed in Cumulative or Differential mode. Count modes are discussed in section 5.2.3 - Sample Time
The sample time is the length of time the unit will sample for. The sample time is user-selectable for 30-9,999 second samples. - Hold Time
The hold time is used when the sample mode is set to auto (continuous sample). The hold time represents the time from the completion of the last sample to the start of the next sample. The hold time is user settable from 0 – 9999 seconds and is discussed in section 5.2.5. - Sample Timing
The following figures depict the sample timing sequence for both manual and auto-sampling modes. Figure 7 shows the timing for manual sample mode. Figure 8 shows the timing for auto sample mode.
The Main Menu is accessible by pressing the MENU key on the Operate screen. The table below and Figure 9 show the Main Menu items. Use the rotary dial to highlight the desired menu item and then press it to enter that menu screen.
| Menu Item | Description |
| Sample Setup | View / change sample settings (location ID, single or continuous mode, cumulative or differential count mode, sample time and hold time) and sample sizes. |
| Toolbox | View / change units, memory, flow, and display. |
| Initial Setup | View / change serial settings, clock, and locations. |
| About | Display firmware version, serial number, service contact, calibration date, and run time. |
Edit Menu Items
To change settings, press MENU to display the Main Menu, rotate the dial to navigate to the desired item and press the dial to display the item view/edit screen.
To edit pick list items (e.g. Sample Setup: Single or Continuous), rotate the dial to navigate to the item. Press the dial to select the item. Rotate the dial to change the setting. Press the dial to save the setting or ESCAPE to cancel and return to the previous screen.
To edit alpha-numeric and numeric values (e.g. Location), rotate the dial to navigate to the item. Press the dial to select the item. Rotate the dial to increment or decrement a value. Press the dial to select the next character. Press the dial for all remaining characters to save the value or ESCAPE to cancel and return to the previous screen.
Sample Setup Screenv
The first sample setup screen gives the user the option to select and edit sample parameters or channel sizes. Figure 10 shows the Sample Setup Screens. The parameters are covered in the following sections.
Location ID
The Location ID is used to assign a unique name to a location or area. This important field is included in sample data records (display and csv output). Use the dial to scroll through a list of custom location IDs. To edit the list, see toolbox location ID in section 5.4.4.
Mode
The sample Mode controls single sample or continuous sampling as illustrated below.
| Selection | Description |
| Single | The Single setting configures the unit for a single sample. |
| Continuous | The Continuous setting configures the unit for continuous sampling. |
- Count Mode
The count mode determines if particle counts are displayed in Cumulative or Differential mode. Cumulative mode displays the particles as all sizes greater than the selected size. Differential mode displays the counts as all particles between the selected size and the next larger size channel. - Sample Time
The Sample Time is the length of time the unit will sample for. In Single mode the unit will stop sampling after this period and in Continuous mode the unit will continue to sample at the sample time interval. The Sample Time is user-settable from 30-9999 seconds. - Hold Time
The Hold Time is the time between samples when sampling in Continuous mode. The Hold Time is a user settable that runs from 0 – 9999 seconds. The pump will remain on during the hold period if the HOLD time is 60 seconds or less. The pump will stop after each sample, and start a few seconds before the next sample if the Hold time is greater than 60 seconds. Hold times greater than 60 seconds will increase pump life, as well as increase operating time because of lower battery usage. This setting will not appear on the Sample Setup screen if Single mode is selected. - Size Setup
This allows the user to set custom particle sizes to measure. The screen sorts sizes from small to large after each size change. Duplicate sizes are not allowed.
Toolbox Screen
Figure 11 shows the Toolbox screen. 
Units
The Units setting allows the volume and temperature units to be selected.
Volume: The DR-528 supports particles per cubic foot (CF), particles per liter (/L), particles per cubic meter (M3), and total counts per timed sample (TC). Particle count information updates while the unit is sampling. Concentration values (/L, CF, M3) are time dependent so these values may fluctuate early in the sample; however, after several seconds the measurement will stabilize.
AT: The DR-528 displays ambient temperature (AT) in Celsius (C) or Fahrenheit (F). 
Memory
The DR-528 can store up to 15,000 sample records in its memory. For instructions on viewing stored data, see section 4.3.3. Because this memory is circular, once all 15,000 records are full, any new samples taken will overwrite the oldest stored sample data.
The Memory screen provides indication of the available memory capacity and a means to completely erase all data currently saved in memory. The Free field shows the percentage of space available for data storage. When 0% is displayed, the memory is full and the oldest data will be overwritten by new data.
Press down on the rotary dial to activate the CLEAR command and erase the unit’s memory. A confirmation screen will appear. Select the CLEAR option on the confirmation screen to continue with erasing the data and then returning to the memory screen. Selecting CANCEL on the confirmation screen will return to the Memory screen without erasing the data. 
Flow
The Flow screen is where a flow calibration is performed. When this screen is selected, a warning will appear to use an external flow meter to adjust the DR-528 flow to 2.83 LPM. Select OK to proceed or CANCEL to exit.
The pump will start automatically when you enter the Flow screen and stop when you leave the screen. Use the following procedure to adjust the flow rate when a periodic flow rate check (Section 8.3) indicates a flow rate error greater than ± 5%.
- Remove the isokinetic inlet.
- Connect a reference flow meter to the inlet fitting on the top of the unit and allow the flow to stabilize.
- Twist the dial clockwise to increase the flow rate and turn the dial counterclockwise to decrease the flow rate until the measured flow rate is 2.83 LPM (0.1 CFM) ± 5%.
- Press the dial to save the calibration. Press ESCAPE to cancel without saving.
The progress bar shows the pump pulse width modulation (PWM) as a percentage. A green progress bar means the PWM is in a good place. An orange progress bar indicates the filter is getting close to needing to be replaced. A red progress bar indicates the filter needs to be replaced. 
Display
The Display screen allows the user to change the backlight brightness from 10-100% and select the display timeout to dim the screen for none, 1, 5, or 10 minutes. 
Alarms
The DR-528 features alarm limits for each channel size. Setting the alarm limit above zero with enable the alarm on that channel. When sampling, if the alarm limit is set and the counts go over the limit then the alarm will be active. By default, the alarm beep is enabled in which an alarm beep will continually go off. Alarms are reset at the beginning of the next sample or turned off if the user manually stops the sample. Setting the alarm limit to zero will disable the alarm on that channel. The maximum alarm limit value is 9,999,999.
Figure 17 shows the Count Alarm Screen.
Alarms are displayed in increasing particle size order. Navigate between the two screens using Next and Back.
Alarm values do not change with the count units setting (TC, /L, CF, M3). In other words, a value of 1,000 will alarm at 1,000 counts or 1,000 particles per liter or 1,000 particles per cubic foot depending on the count unit setting.
Alarm Beep
This screen will enable or disable the alarm sound when an alarm count condition occurs. 
Docking Station
The Docking Station screen is a troubleshooting feature that determines the unit WiFi credentials if it was set up as a DHCP connection instead of a static connection and the IP address changes. The 83529 Docking Station quick setup manual explains how to connect the unit to the optional docking station. Select WiFi Discovery to begin the procedure. 
The subsequent screens describe what to do. Remove the unit from the Docking Station. Then remove the power plug from the back of the Docking Station (it will receive power from the unit during this procedure). Make sure the network switch on the Docking Station is set to WiFi and not Ethernet. Select NEXT and then place the unit in the dock. A green bar will show the progress of the scan.
Once the scan completes the WiFi connection credentials will display on the screen. If the procedure was not performed correctly (e.g. dock plugged in/unit not docked/ network switch set to Ethernet) a time out message will appear. The Docking Station can be plugged back in once the scan completes. Press escape to exit this screen.
Initial Setup Screen
Figure 22 shows the Initial Setup screen. These items are not expected to need to be changed frequently but need to be configured when first using the instrument.
Serial
The Serial setting controls the behavior of the DR-528 serial output hardware available on the optional docking station. The following table lists the Serial settings and describes their meanings.
| Selection | Description |
| Network ID | Unique ID assigned to each device for networking mode (1 – 999). |
| 485 Baud | Baud rate for the docking station RS-485 serial port. The baud rate list includes 2400, 4800, 9600, 19200, 38400,
57600, and 115200. |
| Dock Baud | Baud rate for the optional docking station WiFi/Ethernet port. Same baud rates as listed above. |
| Flow Ctrl | Flow control for the optional docking station Ethernet Netburner (None, XON/XOFF). This should be set to None for USB, RS-485, and WiFi communication and if MODBUS is employed. |
Modbus
The Modbus setup allows the user to choose which communication port to use if employing Modbus. Port options are USB, RS-485, or Network. RS-485 and Network options are available through the optional 83529 Docking Station. Network options are either WiFi or Ethernet and are selected by a switch on the Docking Station. The equipment Modbus address is also set in this screen with values of 1-247. 
Clock
Use the Clock selection to set the date and time. Turn the dial to select year/month/date/hour/minute/second to change. A green box will surround the selection. Press the dial to edit. Turn the dial to change, then press to confirm the change. Press the dial on the SET box to change the settings and return to the Initial Setup screen. 
Locations
The Locations screen allows the user to set up to 10 predefined alpha numeric locations. Each location can use up to 7 characters. To enter a new location, press the dial on the location to change. Rotate the dial to scroll through alpha/number/space options for each character. Press the dial to select each character. All 7 characters must be selected to save the location ID. It is suggested to use spaces for a location with less than 7 characters. 
Password
Users have the option to set a user password. Setting the value to 0 disables the password. Setting it to anything greater than 0 will enable the password. If the password is set, users will be prompted for the password upon trying to enter any setting screens. 
About Screen
Figure 28 shows the ABOUT screen. The ABOUT screen shows the manufacturer’s serial number, the firmware version, Met One Instruments, Inc. service contact details, date of last calibration, and instrument run time. 
Charging the Battery
Caution: The provided battery charger is designed to work safely with this device. Do not attempt to connect any other charger or adapter to this device. Doing so may result in equipment damage.
To charge the battery, connect the battery charger to an AC power outlet and the DC barrel connector to the socket on the left side of the DR-528. The battery charger is universal and will work with power line voltages of 100 to 240 volts, 50 to 60 Hz. A discharged battery pack will take approximately 2.5 hours to fully charge.
When fully charged the battery inside the DR-528 will power the unit for over 8 hours of continuous sampling. For continuous operation, operate the unit with the battery charger attached. Charge the battery before storing the DR-528. Storing a discharged battery will degrade its performance.
The DR-528 can also be charged using the optional 83529 Docking Station. The device will fit securely onto the Docking Station when encased in its rubber boot. If the rubber boot is not used, an 83584 bootless adapter is placed at the base of the docking station to hold the device.
Serial Communications
The DR-528 provides serial communications via the USB connector located on the right-hand side of the unit. RS-485, WiFi, and Ethernet communications are also available with the optional 83529 Docking Station. Refer to the 83529 Docking Station Quick Setup Guide to configure the optional communications. The following sections discuss the various serial communications available with DR-528.
ATTENTION:
A Silicon Labs CP210x Driver for the USB connection must be installed before connecting to the USB Type C port.
Driver download weblink: https://metone.com/usb-drivers/
Commands
The DR-528 provides serial commands for accessing stored data and settings. All commands are terminated by a carriage return. These commands are not case-sensitive. The following table lists the available commands. These commands are available via USB, WiFi, ethernet, and RS-485 hardware interfaces. The settings (baud rate, parity and stop bits) must match the computer setting for proper communication regardless of the hardware interface type.
Settings (must match computer settings):
- Baud Rate = 115200 (USB Default); 9600 (RS-485 Default); 38400 (Dock Default)
- Parity = None
- Stop Bits = 1
- Flow Control = None
The following table lists the available commands:
| Command | Description |
| ? | Help command |
| 1 | Report settings |
| 2 | Report all the data |
| 3 | Report the new data |
| 4 | Report the last record(s) |
| A | Network address command |
| C | Clear the data file |
| E | Stop sample |
| H | Help Menu |
| Q | Exit Terminal Mode |
| S | Start sample |
| X | Exit Terminal Mode |
| AB | Enable/Disable alarm beep: AB 0=Disable, AB 1=Enable |
| AL | Get/Set the alarm limit for a specific channel using format AL c v, where c – Channel number (1 – 8)
v – Alarm limit value (0 – 9999999) (0 = OFF) |
| BL | Back Light (%) |
| CM | Count Mode: CM 0=Cumulative, CM 1=Differential |
| CU | Count Units: CU 0=CF, CU 1= /L, CU 2= TC, CU 3=M3 |
| DS | Report data log channel descriptors |
| DT | Date / Time (DT YYYY-MM-DD HH:MM:SS) |
| HS | Get/Set Hardware Handshaking |
| ID | Location ID |
| LN | Get/Set the location name for a specific location index using LN i n, where i – Location Index (1 – 10); n – Location Name (Capitol Letters and numbers only) (no symbols except spaces) (7 characters max) |
| MA | Modbus Address (1-247) |
| NW | Network On/Off. NW 0=Off, NW 1=On |
| OI | Output Interval OI 0=Off, OI 1=On |
| PR | Print File |
| PW | Enter the password to change settings (if the password is enabled) |
| QH | Report data record header |
| RQ | Report (ReQuest) data record readings |
| RV | Report Firmware Revision |
| RZ | Report Measurement Sizes |
| SB | Get/Set USB Baud Rate. 3=2400, 4=4800, 5=9600, 6=19200,
7=38400,8=57600,9=115200 |
| SH | Hold Time (0-3600) |
| SM | Sample Mode. SM 0=Single, SM 1=Continuous |
| SS | Serial Number |
| ST | Sample Time in seconds (1-9999) |
| TU | Temperature Units. TU 0=C, TU 1=F |
| DISPTO | Manual Display Timeout. 0=None, 1=1-min, 2=5-min, 3=10-min. |
Comma Separated Value (CSV)
The CSV report will be generated for each data inquiry. The format is fixed field length.
Counts Format
Count Data Report
2021-05-10 08:53:10
Serial Number, B12561
Time,0.3(M3),0.5(M3),1.0(M3),2.5(M3),4.0(M3),5.0(M3),7.0(M3),10(M3),AT(C),RH( %),Location,Seconds,Status 2021-05-07 15:39:09,06768198,01445936,00022968,00003180,00001413,00000706,00000353,00000 353,+024.9,030,LOC1 ,0060,0000
| CSV Fields | ||
| Field | Parameter | Example Value |
| 1 | Date and Time | 2021-05-07 15:39:09 |
| 2 | Channel 1 Size 0.3 (TC, /L, CF, M3) | 06768198 |
| 3 | Channel 2 Size 0.5 (TC, /L, CF, M3) | 01445936 |
| 4 | Channel 3 Size 1.0 (TC, /L, CF, M3) | 00022968 |
| 5 | Channel 4 Size 2.5 (TC, /L, CF, M3) | 00003180 |
| 6 | Channel 5 Size 4.0 (TC, /L, CF, M3) | 00001413 |
| 7 | Channel 6 Size 5.0 (TC, /L, CF, M3) | 00000706 |
| 8 | Channel 7 Size 7.0 (TC, /L, CF, M3) | 00000353 |
| 9 | Channel 8 Size 10 (TC, /L, CF, M3) | 00000353 |
| 10 | AT (C, F) | +024.9 |
| 11 | RH (%) | 030 |
| 12 | Location | LOC1 |
| 13 | Seconds | 0060 |
| 14 | Status | 0000 |
Status
The last entry of the CSV output is the status indicating alarms or errors. Status bit combinations are possible. For example, 18 = IOP Alarm and Temperature Sensor Alarm.
| Status Bits | ||
| Bit | Value | Condition |
| 0 | OK (no alarms or errors) | |
| 0 | 1 | Not used |
| 1 | 2 | IOP Alarm (Laser) |
| 2 | 4 | Not used |
| 3 | 8 | Not used |
| 4 | 16 | Temperature Sensor Alarm |
| 5 | 32 | Pressure Sensor Alarm |
| 6 | 64 | Not Used |
| 7 | 128 | Count Alarm |
MODBUS Communication
The DR-528 supports MODBUS communications protocol. The serial transmission is RTU mode. The following MODBUS registers are used to access various readings.
Instantaneous Real Time Readings
| Name | Address | Type | Points | Description |
| Time | 1000 | dword | 2 | Current Timestamp (Unix) |
| Stat | 1002 | dword | 2 | Current Status |
| Location | 1004 | string | 4 | Current Location Name |
| Elapsed | 1008 | dword | 2 | Current Elapsed Time |
| Size1 | 1012 | float | 2 | Current Channel 1 Size |
| Size2 | 1014 | float | 2 | Current Channel 2 Size |
| Size3 | 1016 | float | 2 | Current Channel 3 Size |
| Size4 | 1018 | float | 2 | Current Channel 4 Size |
| Size5 | 1020 | float | 2 | Current Channel 5 Size |
| Size6 | 1022 | float | 2 | Current Channel 6 Size |
| Size7 | 1024 | float | 2 | Current Channel 7 Size |
| Size8 | 1026 | float | 2 | Current Channel 8 Size |
| Count1 | 1028 | dword | 2 | Current Channel 1 Counts |
| Count2 | 1030 | dword | 2 | Current Channel 2 Counts |
| Count3 | 1032 | dword | 2 | Current Channel 3 Counts |
| Count4 | 1034 | dword | 2 | Current Channel 4 Counts |
| Count5 | 1036 | dword | 2 | Current Channel 5 Counts |
| Count6 | 1038 | dword | 2 | Current Channel 6 Counts |
| Count7 | 1040 | dword | 2 | Current Channel 7 Counts |
| Count8 | 1042 | dword | 2 | Current Channel 8 Counts |
| IOP | 1044 | float | 2 | Current IOP Laser Reading |
| AT | 1046 | float | 2 | Current Temperature Reading |
| RH | 1048 | float | 2 | Current Relative Humidity Reading |
| BP | 1052 | float | 2 | Current Barometric Pressure Reading |
| BV | 1054 | float | 2 | Current Battery Voltage Reading |
Last Data Record Readings
| Name | Address | Type | Points | Description |
| Time | 1500 | dword | 2 | Last Timestamp (Unix) |
| Stat | 1502 | dword | 2 | Last Sample Status |
| Location | 1504 | string | 4 | Last Sample Location |
| Duration | 1508 | dword | 2 | Last Sample Duration |
| Size1 | 1512 | float | 2 | Last Sample Size 1 |
| Size2 | 1514 | float | 2 | Last Sample Size 2 |
| Size3 | 1516 | float | 2 | Last Sample Size 3 |
| Size4 | 1518 | float | 2 | Last Sample Size 4 |
| Size5 | 1520 | float | 2 | Last Sample Size 5 |
| Size6 | 1522 | float | 2 | Last Sample Size 6 |
| Size7 | 1524 | float | 2 | Last Sample Size 7 |
| Size8 | 1526 | float | 2 | Last Sample Size 8 |
| Count1 | 1528 | dword | 2 | Last Channel 1 Counts |
| Count2 | 1530 | dword | 2 | Last Channel 2 Counts |
| Count3 | 1532 | dword | 2 | Last Channel 3 Counts |
| Count4 | 1534 | dword | 2 | Last Channel 4 Counts |
| Count5 | 1536 | dword | 2 | Last Channel 5 Counts |
| Count6 | 1538 | dword | 2 | Last Channel 6 Counts |
| Count7 | 1540 | dword | 2 | Last Channel 7 Counts |
| Count8 | 1542 | dword | 2 | Last Channel 8 Counts |
| IOP | 1544 | float | 2 | Last Sample IOP Laser Reading |
| AT | 1546 | float | 2 | Last Sample Temperature |
| RH | 1548 | float | 2 | Last Sample Relative Humidity |
| BP | 1552 | float | 2 | Last Sample Barometric Pressure |
| BV | 1554 | float | 2 | Last Sample Battery Voltage |
Maintenance
Due to the nature of the instrument, there are minimal customer-serviceable components in the DR-528. The case of the DR-528 should never be removed or opened for any reason. Opening or removing the case of the DR-528 voids the warranty and may result in exposure to laser radiation, which can cause eye injury.
Recommended Service Schedule
Although there are no customer-serviceable components in the DR-528, there are service items that ensure the proper operation of the instrument. The table below shows the service schedule for the DR-528.
| Time Period | Item | Manual Section |
| Weekly | Zero Count Test | 8.2 |
| Monthly | Flow Rate Test | 8.3 |
| Yearly | Annual Calibration | 8.4 |
| Yearly/As required | Filter change | 8.5 |
Zero Count Test
Air leaks or debris in the particle sensor can cause false counts which may result in significant count errors when sampling clean environments. Perform the following zero count test weekly to ensure proper operation:
- Attach zero count filter to the inlet nozzle (PN G3111).
- Configure the unit as follows: Mode = Single, Sample Time = 60 seconds, Volume Units = Total Count (TC).
- Start and complete a sample.
- The smallest particle size should have a count <= 1.
- Run this test multiple times to flush out particles in the air stream if the goal is not met.
Flow Rate Test
The flow rate test verifies the sample flow rate is within tolerance. The reference flow meter must be non-loading because the vacuum pump can be loaded down by external restrictions. Met One Instruments, Inc. sells suitable flow meters (PN 9801 or Swift 6.0). The flow rate test is described in section 5.3.3.
Annual Calibration
The DR-528 should be sent back to Met One Instruments, Inc. yearly for calibration and inspection. The annual calibration cannot be performed by the customer because this calibration requires specialized equipment and a skilled technician. Met One Instruments, Inc. maintains a calibration facility for calibrating particle counters according to industry-accepted methods such as ISO and NIST. The annual calibration also includes inspection and preventative maintenance to improve product reliability.
Filter Change
The DR-528 filter cartridge is located on the bottom back instrument panel. A 0.2-micron filter, MOI part number 580302, is used to filter the instrument exhaust. It can be removed by unscrewing the black aluminum filter holders with a coin using the slot in the face of the holder. The frequency of filter changes depends on the particulate concentrations measured.
Flash Upgrade
The DR-528 is firmware upgradeable via the serial connection using a Met One Instruments, Inc. update utility. The new firmware and update utility must be provided by Met One Instruments, Inc.
Troubleshooting
The following section covers some common failure symptoms, causes and solutions. It is important to note that there are no customer-serviceable components in this product. The DR-528 case should never be removed or opened for any reason. Opening or removing the case will void the warranty and may result in exposure to laser radiation, which can cause eye injury.
Specifications
| Performance | |
| Particle Counter Sizes | 0.3-10 µm user selectable (default sizes = 0.3 µm, 0.5 µm, 0.7 µm,
1.0 µm, 2.0 µm, 3.0 µm, 5.0 µm, 10.0 µm) |
| Concentration Range | 0 – 3,000,000 particles per cubic foot (105,900 particles/L) |
| Particle Size Accuracy | ± 10% to calibration aerosol |
| Flow Rate | 0.1 cfm (2.83 lpm) |
| Sample Time | 30-9,999 seconds |
| Hold Time | Adjustable: 0 to 9999 seconds |
| Electrical | |
| Light Source | Laser Diode, 90mW, 780 nm |
| Battery | 7.4V Li-ion battery pack. |
| Battery Life | 8 hours continuous operation |
| Battery Charge Time | Fully changed in 2.5 hours |
| AC Adapter/Charger | Li-ion battery charger, 100 – 240 VAC, 50/60Hz |
| Communications | USB (WiFi, Ethernet, and RS-485 available on optional docking station) |
| Interface | |
| Display | 2.8 inch TFT full-color LCD |
| Keyboard | 2 button membrane keypad with rotary dial |
| Physical | |
| Height | 8.8” (22.35 cm) |
| Width | 3.75” (9.53 cm) |
| Depth | 2.25” (5.72 cm) |
| Weight | 1.00 lb 13.5 oz (0.84 kg) |
| Environmental | |
| Operating Temperature | 0º C to +50º C |
| Storage Temperature | -20º C to +60º C |
| Accessories | |
| Supplied | Operation Manual USB Cable Comet Software
Particle View Software AC Adapter/Battery Charger Iso-kinetic Sample Probe RH and Temperature Probe Carrying Case Rubber Boot Zero Particulate Filter |
| Optional | Ball Flow Meter kit (PN 9801)
Digital Flow Meter (PN Swift 6.0) Docking Station (PN 83529) |
Documents / Resources
 |
Met One DR-528 Handheld Particle Counter [pdf] User Manual 9800, Rev B, DR-528 Handheld Particle Counter, DR-528, Handheld Particle Counter, Particle Counter, Counter |
