Content

Structural features

A. The ESDA consists of vacuum pump, perforated plate, high voltage generator, corona wand, corona wand slider, charging film reel, toner pad, electrostatic powders chamber and humidifier.

B. The charging film reel is inside the unit, and the charging film is output from the discharge port.

C. Two methods to produce electrostatic charge in the air above the surface of the paper: a. place the corona wand on the wand slider and move it over the paper; b. hold the corona wand and wave it over the paper.

Working principle

Under the negative pressure generated by the vacuum pump, both the charging film and the paper adhere to the perforated plate.The high-voltage generator outputs high-voltage static to the corona wand, and an electrostatic field is generated around the exposed electrodes of the corona wand. While the corona wand moves slowly over the perforated plate, the electrostatic field generated by the corona wand drives the charge in the paper to move and accumulate at areas where there are indentations in the paper surface, thus the latent indentations can be developed. Spray the electrostatic powders on the surface of the charging film, and the charge in the indentations in the paper surface will attract the powder particles, thus revealing indented writing in black.

Method of use

A. Place the questioned document on the perforated plate, and cover the questioned document evenly with the plastic charging film.

B. Turn on the power switch to start the vacuum pump, which then sucks air through small holes on the perforated plate. Both the charging film and the document should adhere to the perforated plate tightly.

C. Place the corona wand on sliding support. Turn on the high voltage switch, then the corona wand generates an electric field. Hold the corona wand and push the support move that make the corona wand over the entire surface of the document back and forth for 2~3 times, then turn off the high voltage switch.

D. Place the toner pad on the perforated plate and press the powder spray switch several times until writing with suitable color appears on the plastic electrostatic film.

E. The optimum ambient humidity of ESDA is 50%~75% relative humidity. When the environment humidity exceeds 75%, the testing environment should be dehumidified. When the environment humidity is lower than 50%, the electrical conductivity of the document is poor due to low water content, resulting in a poor revealing effect. In such a case, the document may need to be humidified. Add a small amount of warm water (about 5mm) to the deep tray, place the perforated tray on the deep tray, place the document on the perforated tray, then cover the perforated tray with the shallow tray. Leave it for 10 minutes to complete the humidification.

Product Application

Application areas for our products include crime scene investigation, fingerprint collection and development, footprint collection and development, tool marks collection, trace evidence collection, documents examination, forensic medical examination, forensic evidence collection, DNA collection, DNA disinfection, criminal photography, criminal investigation light source, narcotic drugs test, poison test, evidence packaging, evidence marking, crime scene plotting, crime scene protection, human body protection on crime scene.

Our Service

We can provide reliable product and service for you.

1. Q: Is it a reliable company?

A: Beijing Bulant Police Equipment Co.,Ltd. is a company specialized in forensic product, such as: crime scene investigation, trace detection, fingerprint development and extraction, footprint extraction, micro-evidence extraction, files & documents inspection, gunshots detection, forensic examine, DNA extraction, criminal photograph, forensic light source, alcohol test, traffic scene investigation, drug & poison examine, evidence packaging, consumables in lab, etc.

2. Q: What about the delivery?

A: We can offer the door to door services by air or by sea just depend on your actual request. Such as DHL, UPS, TNT, FEDEX…

3. Q: What is the package?

A: Aluminum alloy case/carton case/wooden case.

4. Q: Do you have any timely technology supports?

A: We have a professional technology supporting team for your timely services. We prepare the technical documents for you, also you can contact us by telephone, webcam, online chat (google talk, MSN, skype, yahoo).

5. Q: What is the payment method?

A: T/T, WESTERN UNION, MONEY GRAM, ESCROW, PAYPAL

6. Q: Do you take part in the world exhibition every year?

A: Yes, we took part in exhibitions every year since 2008.